The former Python said he was furious with Dreamworks for lifting a gag from Monty Python And The Holy Grail without telling him.
In Shrek The Third, Prince Charming is seen riding a horse – but then the camera pans out to reveal he is on a hobby horse with a minion banging two coconut halves together.
Idle, 64, told the Mad Dog & Billie radio show in Toronto: ‘I was shocked. It’s been stolen patently. So we’ll be able to sue their ass.
‘If you steal peoples jokes, I don’t think that’s homage, I think that’s theft.’
Idle voices the character of Merlin in the animated film, which took £61million in its opening weekend at the US box office, and also stars John Cleese.
