OK, this doesn't exactly follow what happens in the book, but you will get the idea.

NOTE: All characters belong to JK Rowling.

Fluffy

A dog named Fluffy guarded a trapdoor

Under the door was danger and more

A Sorcerer's Stine was hidden there

Snape was searching for it everywhere

He went to the corridor on the third floor

To see what was under the trapdoor

Fluffy gave Snape such a fright

That he almost lost his own sight

He almost bought Snape's leg off

It must have felt like an electric shock

Snape started yelling "That blasted thing!"

And he limped right up to the hospital wing