Batman: The Brave and the Bold

Menace of the Conqueror Caveman! (1x17)

Air date: May 15, 2009

31st Century Booster Gold travels back 100 centuries to join Batman and become a celebrity hero. In his quest for fame, he unwittingly enables the immortal tyrant Vandal Savage to carry out his nefarious plot of turning everyone into cavemen and taking over the world!