The brilliant and slightly egotistical beagle known as Mr. Peabody has long been recognized as the world's most intelligent dog-despite his penchant for making the worst puns in the history of wordplay. During his youth, Mr. Peabody was sent to the Canine Academy for the ARFS (Affection, Retrieval, Frolicking, and Sitting), where he was quickly recognized as a puppy prodigy when he recited Fredrich Nietzche's "Beyond Good and Evil" by memory in Latin, Russian, and his native tongue, Dog.

Tired of living alone in his lavish penthouse apartment, Mr. Peabody decided to adopt his own boy. A young orphan named Sherman became his faithful companion following a lengthy custody battle-which Mr. Peabody won because of his unfathomable legal knowledge. In order to exercise Sherman and keep him off his furniture, Mr. Peabody built the WABAC machine, which holds the distinction of being the world's first working time travel device invented by a dog.

When not correcting the course of history on his trips through time in the WABAC, Mr. Peabody practices both yoga and judo, writes sonnets in Sanskrit, and composes twelve-tone duets for swinette and glockenspiel.