"I'll Be A Mummy's Uncle"
King Tut discovers that there is a deposit of the incredibly rare metal Nilanium underneath Wayne Manor. He arranges to buy a small piece of land on the corner of the Wayne estate and hires some contractors to start a slant-mining operation. Batman and Robin realize what his intentions are, and arrange for Batgirl to meet them at the mine's entrance.
King Tut and his men flee down the shaft in a mine car when the caped crusaders arrive, and they crash right through the wall of the Batcave! Tut fits the clues together and realizes that Bruce Wayne is Batman, but they are soon chased out and everything is forgotten after a healthy dose of Bat-nesia.
King Tut has a good time putting a beating on the Bat-dummies when he finds them in the Batcave.