Friiight Night (Goosebumps SlappyWorld #19)

This is Slappy's world -- You only scream in it!
Kelly Crosby is the new kid in school. So far, it's not going so well. He's already gotten lost, had trouble making friends, and annoyed the monster that lives in the school basement.
That's right.
This new school has a monster. Every year, at a party called Friiight Night, one (un)lucky kid is chosen to be the monster's special guest of honor. Guess whose luck is about to run out?