This was the winner of the three options from my oneshot fanfic, Open ended. I hope you all like it.

This is a Beast-boy centric AU, no pairings but big BB and Cy friendship. Beast Boy will be OOC in the beginning, but it is for good reason.

Disclaimer, I don't own.

A young teen, completely green from the tip of his forest hair to the bottoms of his lime feet, sat curled upon himself in a cage much to small for a boy half his age. A dark cloak covered his small prison, but did not spare him from the sounds, smells, and vibes of the world around him. The boy leaned his head against the cold metal bars, closing his tired eyes and simply awaiting the fate he knew was to come.

The child had led a horrible life, and he knew that it was likely to never get any better. He had been bitten by a monkey and given a horrible illness, been experimented upon and saved from death at the hands of this disease only to awaken as a freak and monster. He had watched as his parents died, full of "super powers" but unable to use them to save the only things which truly mattered to him. He had been stolen from his loving African Tribal father to become a thief for people who hurt him. He'd had to live for years living with two men who made him steal, made him fight, and gave him nothing but abuse and pain for it. He'd had to make the impossible decision to keep the two men from killing each other in a fight, knowing that his only reward would be scars and bruises. He'd been bought and sold to dozens of different owners and masters. People who had bought him as a pet, as a guard dog, a fighter, and slave.

The marks of these lives showed on the teen's green skin. Brands from different owners covered his hands, his shoulder blades, even his chest. The sheer glimmer of once burnt skin showed all over his body, and if one studied an X-ray of him closely they would see the evidence of several broken and healed bones. Possibly the most frightening were the thick scars that wrapped around the boy's thin form. A frame much too small, too skinny for a teen his age.

There was no question that this child was malnourished. His bones could be seen through his green pigment, skin-tight jumpsuits hung loosely on his frame. His current owners were selling him and no longer saw it fit to listen to his constant pleas for vegetarian meals. Not that they had listened much when he was theirs. Instead they cruelly continued to feed him whatever they wished, usually consisting of that nights leftovers and scraps. When faced with the choice to either eat meat or go hungry he had always chosen not to eat... so far at least. With each meal of parsley and water his resolve and determined weakened.

The boy's eyes cracked open slightly as the sounds of absolute chaos sounded, they widened all the way as the sound steadily increased. His ears perked and he pushed himself up slightly, only to fall back in a weak exhaustion. He knew that should his Master come his exhaustion wouldn't matter, he would have to do whatever was commanded of him. As he leaned back against the metal of his small cage, he knew that despite his curiosity he was better off taking advantage of this brief moment of rest. He wouldn't see anything anyway, the cloak made sure of that. His thick collar clanged against the metal bars of the cage when he sat back. He sighed as it reminded him of his restrictions, but otherwise ignored it as he settled down. Relaxed but alert, the green child leaned back against the bars, his ears perked and his sensitive nose quivering.

The sounds of chaos continued to reign through the warehouse, screaming, guns, metal hitting metal and concrete, and the dull thuds of bodies connecting and being thrown into walls. It was the sounds of a fight. It was a raid, the child suddenly realized. He idly wondered if he was going to be stolen. It wouldn't be the first time. Not all of his owners had actually bought him from another. He was extremely accustomed to criminal rivalries. If he was free his Master would have him fight, but if he were taken while still in his cage... well there was nothing he could do then. He grimaced as he rubbed one of his worst phantom wounds. The thieves were usually the most violent.

He straightened slightly as the sounds of running feet distinguished themselves above the general clatter. The feet were coming straight for his cage. The green teen straightened as the sound increased, fear coursing through him. If this was a thief coming to take him away, he would have nothing to look forward to than practical torture and the pain of a new, cruel Master. The steps stopped right in front of his cage, a man's rapid and harsh breathing sounding. The boy felt only a small bit of relief as he recognized the scent of his current Master through the cloak. After all, his life would continue to be horrible no matter who was coming. His relief lasted less than a moment however, for the cloak was torn off the front of his cage almost before the man stopped. The child blinked in surprise as his eyes attempted to get used to the bright light suddenly flooding his vision.

His Master was crouched in front of his cage, key ring already in his hands. Sweat peppered his Master's forehead, and a new bruise could be seen forming. His eyes were wide and the child could smell the scent of fear on him as the man's hands shook trying to unlock his cage door.

"Be ready," The man commanded, and suddenly with a strange influx of power it was not a lime child in the cage, but an evergreen lynx, it's lithe body coiled in preparation to leap. From this position he could jump out of the cage and be in the form of an elephant, lion, or a creature even more ferocious in less than a second. The man cursed violently as his shaking hands struggled to unlock the cage. He continually glanced behind him as though expecting the very shadows to attack.

He cursed as he once again slipped and the key fell short of the lock. He glared at the bars surrounding the child, and the boy knew that for once he was cursing the restrictions. The cage was designed so that should he attempt to escape by either turning into an animal small enough to slip through between the bars, or large enough to break the barrier electricity would shoot into his collar until the boy either gave up his escape attempt or perished.

Finally the key clicked into place, just as the shadowy figures of four teens appeared in the doorway.

"Beast, attack!" The boy's Master yelled and with a burst of its powerful feline hindquarters the lynx leaped out of the cage, transforming into a lion before his paws even touched the ground. The emerald king of the jungle rose his head with a ferocious raw before charging upon the enemies of his Master.

The teen was a fighting machine, trained cruel and constantly for years to hone his powers, his fighting technique. Masters of strategy and animal behavior had drilled him mercilessly until his animal instincts and human mind were perfectly melded so that they could create the perfect form of attack. Martial artists and weapons masters had trained him, imparting their knowledge upon the unfortunate teen. He was no longer some kid trying to fight and given mysterious powers, he wasn't a hero who trained a few hours a day and fought the bad guys whenever they showed. He was a machine, trained brutally and constantly by the most knowledgeable, most skilled, and most dangerous individuals that existed. He was a Beast.

He shifted into a cheetah as he charged, leaping forward with astounding speed. He was inches away from the group in less than a second, shifting to the larger lion as he leaped at the group. The leader, a teen boy with spiky hair and a bright outfit, incredibly dodged to the side right before the green feline hit. However, the larger male smelling of both human and machine behind him was not so swift. The green lion's weight landed fully on him, knocking the large male into the two girls. For a millisecond instinct and human strategy argued, unsure of whether to treat the opponent as a human or robot, but he couldn't to dwell on it long, he had to make a decision and act upon it immediately. He knew that from experience. In the end he decided on the later and jumped back, knowing that his current form, whose strength was teeth and claws, would do little to fight against the man's metal and machinery.

However, he had no time to shift and go back in for another blow at the robotic teen, for as he jumped back his instincts screamed that he was under attack. Shifting into a smaller target, a mouse, and jumping to the side he narrowly missed the impossibly fast attack of a bow staff. It was the fast, spiky-haired one. The green weapon dodged as the teen attacked, constantly shifting to various different rodent forms. The teen was fast, one of the fastest opponents Beast had ever had. It was all that he could do to avoid and learn the other's technique, much less fight back.

It wasn't until a cup covered in black energy covered his gerbil form that he remembered that the boy had friends. For a moment a light of fear lit in his heart. He was a lone wolf, fighting a pack. Never a good thing. Of course, he had been trained to fight against large numbers but he'd seldom come into serious battle with one as skilled as the brightly colored teen. If all of the group had such skill then this could certainly be a true battle. He could feel his animal instincts bubble at the thought, hungry for the fight, for blood, for the kill.

He burst from the black cup in the form of an African elephant, swinging his large trunk towards the human scent. He trumpeted in triumph as he felt the long appendage knock down two of his foes. The fast male and a female in a long cloak. His trumpet turned to one of shocked surprise as a ray of green light blasted into his large chest, a red-headed female flying at him with glowing green eyes. He turned into a lime spine-tailed swift and weaved around the flying girl. Just as he expected, she stopped in confusion to follow him with her eyes. Taking advantage of the pause the green teen flew above her, shifting into a peregrine falcon and diving straight into her back at over 200 miles per hour. The girl yelled in shock as he hit her, falling down to the ground below.

"Starfire!" spiky-head yelled, rushing to his fallen comrade.

However, the green boy had no time to celebrate his victory before a blast of light blue energy nearly singed his tail feathers. It was the half-robot. With the echoing caw of a predator the falcon dove toward this new foe, changing into a large hippo just before he hit the robotic teen. The green boy felt shock when rather than crushing the robot as he expected, the large teen grabbed him and heaved him into a nearby tower of boxes. As Beast landed he instinctively shifted back to his human form, holding his head in one hand as he felt a recent wound reopen. He grimaced as his hand came away covered in blood and winced in pain before standing unsteadily and turning into a gorilla.

It was no wonder why he was having such trouble. He hadn't had a proper meal in days and injuries from training covered his body. He hadn't had more than a few hours rest in week s. Those were all excuses though. Masters did not listen to excuses. Excuses led to nothing more than punishment and pain. With a shuddering sigh he rose in his primate form and pushed through the boxes until he faced the teens again. His heart froze when he saw them. They had regrouped and were waiting for him.

The flying redhead was floating near the ceiling, both her eyes and hands glowing a bright green. The female in the cloak stood next to her in the air, a disk of energy as black as night holding her up. Her eyes glowed white and the black energy covered her hands. The robot-man was on the ground, pointing his arm-canon at the gorilla as it came out from the boxes. The leader stood to the side, his mask bent down in a glare as his staff and some projectiles stood ready in his hands.

With a barbaric roar the green boy hid his intense fear, showing it as anger as he charged the one nearest to him. The leader shouted his rallying cry, "Titans, go!" And the two clashed once again. The next few moments were pure instinct and adrenalin as the five teens fought viciously. The lone green shape shifter was almost entirely on the defense, only occasionally landing a blow. Had it been a matter of simply defeating the green animals then the four titans would have quickly been counted the victors, but the green creature was too slippery for them to catch. The spiky haired leader, a teen called Robin, stepped back to marvel at his enemy's endurance. The green thing had been in nearly constant movement for who knew how long, yet he showed no signs of slowing.

He watched as his teammates fought the strange colored animals, searching for an exploitable weakness. Suddenly he heard a noise behind him that reminded the Titan why they were in that room in the first place. The leader of a major smuggling ring had been running business in this warehouse for months and they had finally found him. After the Titans had started demolishing his pitiful excuses for guards the man had run into this room, setting that green creature after them. As long as the blueprints that his teammate Cyborg had dug up were correct, there wasn't any way out of this room other than the door they had been battling in front of. That meant that the ring leader was still in the room. Robin looked back to see Cyborg blasting crazily with his canon as an evergreen bat flew at his face. He turned back to where he'd heard the noise when the robotic teen succeed in swatting the bat away, sending it back into the boxes where it quickly emerged as a growling grizzly.

The Titan leader went deeper into the room and farther away from his friends, searching the shadows for the man whom he knew was hidden amid the boxes and supplies. Finally he heard the slight sound and grinned. He had finally found his quarry. Starting into a sprint he turned around the corner to see the man he'd been searching for hiding behind a large crate. The man looked up with horrible fear as he saw Robin and gripped a small remote he held in his hand.

"Protect!" He yelled, his voice cracking with fear. "Protect!" As he spoke he pressed a button at the center of the remote. Suddenly a horrible scream erupted from where the battle still raged. A scream that Robin knew did not come from any of his teammates.

"Protect!" The man called again, and suddenly the form of a large bird rose over the boxes, turning into a large animal and crashing into Robin horrendously. The shape-shifter was now a bear, his eyes wide with pain and fear, tossing his neck from side to side as the collar sparked slightly. The boxes erupted with a crash as the rest of the Titans resumed the fight, each one housing a worried, unnerved expression as they battled the now raging creature. Robin however no longer had eyes for the green beast, instead he was focused on the man who was currently attempting to escape in the confusion. The young hero gave chase, leaving the crux of the battle to his team. The man looked back as he ran, panic once again overriding his features.

"Protect!" He yelled once more, hitting the button. Again, pained yelling erupted from the battle and Robin soon found a cheetah attempting to sink its teeth into his leg. He jumped over the creatures head, turning in midair and delivering a swift kick that the creature was unable to avoid. He was finally slowing, though if it was because of exhaustion or the attacks of pain the Titan did not know. The boy wonder swung his bow staff at the cat, only for it to be deftly avoided. The changeling shifted to a ram and Robin huffed as the large round horns knocked the wind out of him. Suddenly the goat was blasted back as a dark-clothed crate shot into him. Robin nodded his appreciation as his team once again flooded into the fight.

"You go after the guy," The dark clothed empath Raven said to the leader as she fought.

"Yes, leave the fighting of the multitude of earth creatures to us." The alien Starfire called as she blasted said multitude of creates with a green starbolt.

"We won't let him chase after ya this time." Cyborg ended, and Robin nodded and sprinted off to find the man once again. This time however, he tapped into his extreme talent for stealth and was upon the man before he knew it. Within seconds the smuggler was bound, Robin smirking over him as he held the small remote. This guy hadn't had a chance.

"Protect! Protect!" The man called, though unable to use the small device. Even so there was a crash as a green wolf burst through a stack of crates, a snarl on his face. Robin turned as quick as a flash and hurled an exploding ball at him opponent, his eyes widening as he saw the black, blue, and green energy shooting at the canine from behind. Each of the four projectiles hit the emerald wolf at the exact same time.

The creature yelped as he was hit, sounding more like a puppy in pain than the snarling foe they had seen. There was a strange, uneasy silence as the green creature's body smashed into a wall, once again landing behind one of the warehouses's numerous piles of crates. This time however, the group didn't wait for him to recover. The four rushed to were his smoking form lay, Robin hauling the villain with him. They stopped as they finally saw him, no longer the animistic fighting machine they had been accustomed to, but a small, underfed, and greatly scarred green boy laying unconscious with his cloths shredded with burns from the fight. Blood dripped from a wound on his head, as well as several other places. There was a gaping hole in the side of his shirt, smoke curling off the edge and a horrible looking burn underneath it. The four Titans shared a glance, knowing that it was there combined attack which caused the wound.

Robin frowned as he neared the teen. This had not been what he'd been expecting to find when they had the chance to finally see their foe. He then looked down to the smuggler and the remote and decided that he probably shouldn't be so surprised.

The unconscious boy whimpered slightly and his eyes slit open. Suddenly he jumped to his feet, crouched in ready position.

"Freeze!"

Cyborg, Raven, and Starfire's hands glowed with energy and Robin instinctively pointed the remote at the teen. The boy froze, though his eyes were not locked on the numerous painful weapons which had subdued him just moments before, but on the small, simple device in Robin's hand. The villain held by the heroic teen squirmed in his grasp.

"Fight! Protect! Attack!" The man called. Each Titan tensed, but the boy did not move and his eyes did not leave Robin's hand. This spiky haired boy held the controller. The green boy slowly rose one hand to brush against the collar on his neck. He who held the controller controlled the collar, they controlled the pain. Whomever held the controller was Master. It was how he was trained. He now belonged to this teen whom he had just been fighting like an enemy. His heart pounded in his chest as he anticipated the punishment certain to eventually come. The boy's old Master cursed.

"No! Ignore that, Beast! I am the Master! You listen to me, ME! Not this boy! Listen to me! Attack!"

Still he did not move. His eyes were still locked on Robin, his body still in his battle stance. Robin looked down to the irate villain, to the remote, to the green teen. "Uh... at ease?"

Suddenly the boy's stance relaxed, shifting from battle-ready to a simple standing position. The rest of the Titans relaxed as well, the glow faded from the girls' hands and Cyborg's arm returned to normal.

"No!" The villain cursed, but no one was paying him any attention. Each of the hero teens had their eyes locked on the green boy standing with his gaze on Robin.

"Well..." Cyborg began slowly. "That was weird. What is that thing?"

Robin frowned as he examined the device. "It's a remote. He would press the button when calling for this... what did he just call it, Beast? He hit it when he was calling for him."

"So that's what made him freak out like that."

"What happened when he pressed it? I was too far away to ever see."

Starfire answered the boy wonder's question. "The green shifter of shapes would cry out in extreme pain and grip the collar around its neck. Then it would disappear and find you and this man."

"A shock collar." Robin concluded. Cyborg nodded.

"A pretty powerful one at that. Here let me see it."

Robin nodded and handed the remote to the larger teen, accidentally jabbing it near Beast as he did so. The green teen flinched visibly. He shook with fear as he wondered what punishments these powerful new Masters would give him for fighting against them. The group noticed the flinch and each member frowned. Cyborg moved to put a hand on the green boy's shoulder.

"Hey, its okay. I'm not going to hit the button, I promise."

Beast flinched at the contact as the metallic hand touched his shoulder, accustomed to any touch bringing pain. The frowns of the group deepened. Suddenly voices sounded from another room, the police were finally here. Robin began to drag the smuggler to the voices, only to stop when Raven's monotone voice sounded.

"So what are we doing with him?"

Robin stopped, turning back to meet the eyes of the terrified green weapon. He sighed. This kid was a mystery. He wanted answers. Was the boy really just following orders because the smuggler had the shock collar or was he a villain as well? Did he enjoy fighting and hurting others or was it simply something he was ordered to do? Did it matter? Was the kid too far gone into a life of simply obeying orders to be saved? He may end up putting the boy in jail anyway, but Robin wanted some answers before he decided on anything.

"Take him back to the tower for now. Something about this whole situation was strange. I want to get some answers from him about a few things first, if he can talk that is. You guys head back now and get one of the quarantine cells ready to keep him in and take care of some of those wounds. I'll handle things down here."

The Titans nodded. Cyborg's grip on the green teen's shoulder tightened slightly and the boy flinched again, making the semi-robot sigh.

"Come with me."

The boy immediately hastened to obey, keeping pace perfectly with the robot until he was placed in the passenger seat of the T-car. Cyborg sighed as he handed the remote to Raven, knowing that she would use it if necessary. That didn't seem likely however. The child was the picture of obedience, never lifting his head or moving suspiciously in the least. Still, better safe than sorry.

Beast looked out of the window from the corner of his eye as one of his new Master's drove him to what he suspected would be his new dwelling place. He had never had Masters so young before. They were nearly his age. He did not know if they would be kinder or crueler than most masters. He did not know if they wanted him to steal or to guard or fight or something else entirely. He knew nothing other than the deep set animal instinct that called to him, shouted in his mind that these Masters would be different than any he had ever had before.

He shifted slightly in the seat, taking care to make sure he did not seen violent or appear to be attempting to escape. The girl in the cloak who held the remote raised it anyway, but she didn't press the button. He breathed in relief and once again turned his eye to the window, never moving his head. He noticed that blood from his head wound was getting on the seat and mentally wined. His Masters would not be happy about that. He closed his eyes in despair. He certainly wasn't getting off to a good start with these Masters. There was already so much for them to punish him for. He searched the vehicle with his senses, becoming accustomed to the scents and sounds of his new Masters.

It wasn't long before he had a complete mental picture of the vehicle, all without moving his head. Suddenly the thought occurred to him that he didn't smell his cage. His Masters had left it behind. That was his last thought before hunger, exhaustion, and the intense pain from the collar, burns, and the fight finally overcame him and he lost the battle of consciousness.