Pocket Sized Rudy is a student at Wagstaff School. He has so far only appeared in "Carpe Museum" when Louise discovers that she is paired with Rudolph Stieblitz for the field trip to the Museum of Natural History. She ponders whether this is him or Regular Sized Rudy and Regular Sized Rudy comes forward. She says "Oh thank God," and Pocket Sized Rudy comes forth with a small hand and points it at her face, saying "Hey, what's the big idea?" in a raspy, tiny voice. The rest of his body was not shown. The response he receives by Louise is "Rudy, geez, wear a bell."
On May 30, 2016 Loren Bouchard responded to a fan's question on Twitter about whether Pocket Sized Rudy would be heard from again. The post included a picture of a script where Pocket Sized Rudy is mentioned in dialogue.