Born on April 3, 1925, Merlin was a torpedo man aboard U.S. Navy destroyers during World War II. He studied acting at the Neighborhood Playhouse in New York and appeared in the ensemble in the original 1948 Broadway production of "Mister Roberts," starring Henry Fonda.
From 1950-54, Merlin starred as Roger Manning on the kids TV program Tom Corbett, Space Cadet, based on a comic strip.
He moved to Hollywood for a role in Six Bridges to Cross (1955), starring Curtis, then appeared with Mamie Van Doren in Running Wild (1955), with Dale Robertson in A Day of Fury (1956), with Tom Tryon in Screaming Eagles (1956) and with Ann Sheridan in Woman and the Hunter (1957).
In 1958-59, Merlin portrayed Lt. Colin Kirby on The Rough Riders, an ABC series set in the aftermath of the Civil War.
His credits also included the