Mother Monster to Appear on Season 23 finale of 'The Simpsons'‎

Last night the long-running comedy cartoon show celebrated its 500th episode, with a controversial cameo from Julian Assange, the man behind the Wikileaks scandal.

Speaking to E! Online about Gaga's cartoon cameo, the show's creator, Matt Groening said: "The great thing about having Lady Gaga is that she came in a number of times and always with a different get-up.

"Like, she'd leave the room and come back in after a break in a completely new getup.

"It was unbelievable. The only time that she ever took off her hat was when it was banging into the microphone."

When asked about other celebrity guests that are on the wish-list to appear on the hit cartoon show, Nancy Cartwright (the voice of Bart) said: "I think that'd be fun... to play with Hugh Jackman. They'd do a song and dance that'd be fun! A musical!"

The Simpsons first aired on December 17, 1989 and is currently on its 23rd season.