In the 1964 Cold War satire Dr. Strangelove, which actor famously played three distinct roles: Group Captain Lionel Mandrake, President Merkin Muffley, and the title character?

Peter Sellers

Sellers was originally intended to play a fourth role, the bomber pilot, but was replaced after an injury. His versatile performance helped define the dark comedic tone of Stanley Kubrick's nuclear war masterpiece.