This sort of sounds like an oath the twins would have made once they decided they were going to cause mayhem and mischief.

Well, as you can see I am Kita Kudai, not J.K. Rowling, so I don't own Harry Potter in any way, shape or form.

Innate jokesters fear no punishment

So take to some mischief.

Open your arms.

Let devilish delight

Embrace you.

May your arsenal of

Naught Pranks and skillful

Lies ad you in dodging trouble

Yet you cannot deny the thrill you feel inside

Swear to cause mayhem, mischief and chaos

While fighting to keep your nose clean.

Extend your ears,

And listen to us – the

Rule breakers.

I'm under the impression

My brother and I are

Under appreciated in our fine art.

Poor soul,

To never know the joy

Of getting caught but

Narrowly escaping

Obvious punishment.

Gone are the times

Of complete and utter

Obedience.

Don't live a life controlled by others.

I Solemnly Swear I am up to no Good