He is portrayed as a slow turtle (hence his name), in the sense that he is regularly late as well as likely being mentally retarded, and often says very random things (ex: "Crayons taste like purple," "... the green ones make me horny," "... drumsticks can also be chicken") in the manner of Ralph Wiggum from "The Simpsons." Tardy also ends some of his sentences or when he is frightened with a high-pitched squeal much like Leonardo DiCaprio's character Arnie Grape in What's Eating Gilbert Grape. In the opening credits, it's said that he graduated from Harvard at the head of his class.
When Fox cancelled the series, the puppet for Tardy the Turtle was "stolen" as FOX claimed copyright to it.
Someone that resembled Tardy makes an appearance on the IFC DVD in one of the pre-episode audio introductions.