The Harry Potter Hallowe'en spoof was a great success.
And Simpson's creator Matt Groening is a huge fan of Harry Potter anyway.
But now, he's gone one step further letting JK playing herself.
When Newsround first told him a few years back that JK loved The Simpsons too and asked if he'd include some Potter references, he was very pleased.
"Wow, I am honoured, my kids have devoured all of the books. No doubt we'll do some Harry Potter references."
That promise has now come true, although there's no word yet on when the new episode featuring JK will hit our screens.
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