Tyler isn't nice to the other kids at school. He doesn't care about anyone until he gets to know the class pet, a white rat named Snowball. Then Tyler tells everyone his new name is Rat Boy! Now all the kids are afraid of him. His teacher tries to talk to him about how he can be a better friend. But Bully Rat Boy doesn't need any friend but Snowball. Then one day Snowball chews the string on his cage door and escapes. The children can't find Snowball anywhere. Rat Boy feels awful. He even hangs reward posters around the school. When the cook finds Snowball in the storage closet, she tells Rat Boy to grab a friend and catch the rat. But who will help Rat Boy? He has no friends.