The Cartoon Network programme has drawn comparisons to the light-hearted 1960s live-action Batman, which starred West as the Caped Crusader.
According to movie website Collider, an anonymous creator from the show leaked the story during the San Diego Comic-Con International.
"Julie Newmar is playing Martha Wayne, and playing Bruce's father Thomas Wayne will be Adam West! I think they're very appropriate parents for Batman," they said. "I should probably not be revealing this."
Newmar also has roots in the '60s television series, being one of three actresses to star as Catwoman in the show.
Brave And The Bold producer James Tucker confirmed that the episode in question will draw from the plot of the popular DC Comics series The Untold Legend Of Batman. Released in 1980, the plotline revealed that Thomas Wayne once fought mobsters at a party, ironically dressed as a giant bat.