Rush said his role as a ghostly pirate in "The Pirates of the Caribbean" gave him the edge he needed to play the late British funnyman in "The Life & Death of Peter Sellers."
Rush told the World Entertainment News Network he was convinced the producers had the wrong guy in mind for the role.
"I thought I'm an Australian and he's English," he said. "He's stouter and shorter than I am. And hairier."
Also, he didn't like the first draft of the script. But, after playing grizzled sea dog Captain Barbossa in "Pirates of The Caribbean," Rush took to the role.
"I was working with a very big hat and a feather and a monkey on my shoulder, and I just felt a little cockier," Rush said.