He is first introduced in the episode Hello Stranger when everyone in Carl's class can bring a pet to school. When the teacher is absent, he bites Carl causing Carl to suddenly behave strangely like a monkey. In Cry Wolf Mr. Licorice is seen in Stuart's presence when Darren buys a book report from him in the boy's bathroom. In Deja Who Mr. Licorice causes Hoodsey to fall from the swing which results in Hoodsley temporarily suffering from amnesia. He runs away from Brandon in Never Can Say Goodbye and is found by Carl and Hoodsey in a pet store. He also participates in a pet talent show, but he doesn't follow Brandon in his act, instead stealing his picolo and showing of his musical talent. He doesn't win however.
Mr. Licorice doesn't seem to like Brandon very much and is sometimes the cause of Carl and Hoodsey's misadventures.
He often wears a pullover and a blue scarf.