A man time-travels to the date of the assassination of an American leader who supported justice for African-Americans (Dr. Martin Luther King, Jr. rather than Abraham Lincoln), attempts to prevent it, and finds a minor repercussion.
When Griffin shows Carly one of his pee wee babies, the penguin's name is Peter. Which is a reference to The Twilight Zone Back There, where the main character of the episode is named Peter Corrigan.