George Clooney is planning a massive prank on Brad Pitt and we can't wait for it to unfold!

Los Angeles - George Clooney plans to ruin Brad Pitt's career with a prank.

The 54-year-old actor is known for his love of gags and admits he has spent years working on a particular joke to play on his friend and Ocean's Eleven co-star.

He said: "I am working on a prank that will end his career. If you take the time, if you're willing to sit on one for a couple of years, and just plant the seed... there's no rush."

George - who is married to human rights lawyer Amal Clooney - recalled the time he pranked Brad with a bumper sticker.

Speaking at the Adobe Summit in Las Vegas, he said: "I got a bumper sticker in the shape of a pot plant that said "Fuck cops" and I put that on the back of his Toyota Prius.

"Because there's no way you're not getting arrested with that."

The Monuments Men star also admitted he sent Meryl Streep a DVD made by a dialect coach and signed it from Brad, while he also arranged for the Fury actor to receive pitch letters, which he pretended were from Tom Cruise and other stars.

But his 52-year-old pal - who raises six children with wife Angelina Jolie - is no stranger to pranks himself and George admitted he fell victim when filming Ocean's Eleven and Brad convinced Italian shoemakers that the actor would only be referred to by his character name.