25 props for solving my Harry Potter riddle!!! Up for the challenge?

I asked this riddle on the Harry Potter fórum and not many people seemed to be interested(although it's still on there, if you want to try)
so..... I'm posting it here to in hopes that someone will finally solve it!!!!!

I upgraded the prize for the 1st correct answer from 15 to 25 props and me as a fã if I'm not already!! If I see many people struggling I will give a hint!!!!


"You saw some of my kind before,
but I was the first you heard.
I was used to escape trouble (though it led to much more)
the squib would've had you cornered
but I let you through the door."

Can be anything of the Harry Potter world - keep your mind open!!!!