"I've done animated voiceovers before," she told E! News exclusively. "I'm an animation whore, but I've never had a large part like this."
But big or small, Rivers made it pretty clear that size doesn't matter. That is, when it comes to the long-running Fox series.
"I adore The Simpsons. It's so clever and so funny on so many levels. So when they called and said, 'Do you want to do it?' without even reading a script I said, 'Absolutely.' Didn't read the script until yesterday," she revealed.
As for the New York agent she's bringing to life on the show, Rivers described her as "tough," mouthy" and "funny."
"My character has nothing to do with me," she said. "It's such a stretch."