Despite Danny seeing the dog only occasionally, Cujo was largely associated with Phantom.

Danny himself didn't actually know why ghosts continually mentioned the dog— in truth it was because they could see what he could not. Cujo's core orbited— practically intertwined with— Phantom's.

That of course meant that Axiom's chaos was not the only Cujo caused mess that Danny was blamed for.

xXx

The first time it happened, it was actually not even Cujo's real fault, let alone Danny's… for Skulker was trying to hunt the adorable little dog.

"I don't know why Phantom would own such a pathetic, simpering creature," Skulker ground out as he stared at the big, red, puppy eyes. "You are valuable for your connection though, despite your uselessness," Skulker informed the pup as his suit weaponized.

Cujo cocked his head, curious for a moment. And then he grew, huge and snarling.

Skulker only got an eep out before the giant dog grabbed the metal armor and shook.

xXx

"Your dog destroyed my suit!" Skulker moaned at Phantom, angered and aggrieved.

Danny took just one look at the sparking, chewed up mess and guffawed laughter. "I'll tell him he's a good dog, then."

Danny just considered this a funny lucky break.

xXx

It got more common.

xXx

First Skulker, then it was Ember with a chewed up guitar, Johnny with a wrecked bike, and even the Box Ghost with a pathetic display of boxes mashed into shapes that couldn't even be described as real cubes anymore.

Danny was a C-average student, but even he could connect the pattern between the ghosts he'd fought recently.

xXx

"You don't have to protect me," he laughed at Cujo the next time he saw him. The dog just woofed, wagging his tail. "If anything, you're just ticking them off."

This caused Cujo's ears to fall, and Danny scrambled for a cheering up promise.

"Whaddya say we work together to keep 'em out of Amity Park? Then they won't be mad at you for hunting them down!" Danny said in an excitable voice as though talking to a child.

Cujo barked and wagged his tail.

xXx

Ghosts started learning about dog whistles quickly after that started.