Emmitt is a minor character. He is P.S. 38's custodian.
Emmitt once was cleaning when Nate and Teddy walked into school the day before school started. Nate told Emmitt he needed to check something in Mrs Godfrey's room. Nate came running out saying "It's still there!" Teddy and Nate then started laughing, although it is unknown what was inside the room. Then Emmitt thought to himself, "A custodian knows everything, a custodian knows nothing."