Mr. Sparks

Mr. Sparks was Greg's math teacher earlier in Greg's year. Every time he wanted his students, including Greg, to remember an important math concept, he stands on a chair. But one time, while he was standing on a chair, one of the chair's legs broke and he fell down. He broke his collarbone due to the fall.

Greg explains Mr. Spark in Cabin Fever on pages 29 and 30.