B. F. Skinny

B.F. Skinny is a talking rat who appears in JumpStart Adventures 5th Grade: Jo Hammet, Kid Detective.

He is the messenger of the whole operation. He delivers Martin's coded messages directly to Jo Hammet at the museum. He calls Jo "lady" other than her real name. He also calls the janitor a "guy with a broom". He's a play on American scientist B.F. Skinner.

According to Martin, "he can speak English, but latched onto the old comedy routines of the movies we used to watch in the lab. Now he only speaks in bad jokes and tired cliches, but you've gotta love the little guy!"