Mr. Peabody and Sherman is a show that presents the audience with educational and comical segments about the adventures of a boy and his dog. Mr. Peabody is a dog that displays a high level of intelligence and owns a laboratory. The boy, Sherman, is Mr. Peabody's pet. Mr. Peabody rescued Sherman from some bullies and he keeps Sherman around for companionship reversing the roles of the master and pet relationship. Both characters retain their physical forms with Mr. Peabody walking on all fours and Sherman displaying the personality of a child who is inquisitive and venturesome.
In order to educate Sherman, Mr. Peabody builds a WABAC machine which acts as a time machine that takes both of the characters back in time. These points in time are usually significant historical times such as the Battle of Bunker Hill and the Battle of Yorktown during the American Revolution. Other times, the two characters observe important people in history like Napoleon, George Armstrong Custer, and Leonardo da Vinci. The historical event is often portrayed in a comical fashion with characters using puns to present the humor.
The WABAC machine can have negative consequences on the past due to Mr. Peabody adding a feature to the machine that allows both him and Sherman to interact with the individuals they meet up with in their adventures. Oftentimes, the time travel disrupts the timeline of history and causes certain historical events to never happen or happen in a manner that does not reflect history. Mr. Peabody and Sherman are then tasked with fixing the timeline and attempting to restore history.
Near the end of the episode, Mr. Peabody and Sherman's actions resolve any negative consequences of their time travel. However, their actions generally result in history occurring in a different manner than what is presented in the average textbook. Sherman always questions Mr. Peabody's interpretation of the event, but Mr. Peabody always insists that his version is correct. Every episode ends with Mr. Peabody telling a joke that is usually a pun taken from either the person or the event that they just witnessed. Then, Mr. Peabody and Sherman return to the present and try to decide which time they will visit in the next episode.