From his wiki entry
"Daryl Frank Dragon (born 27 August 1942, Los Angeles, California) is a keyboardist, known as Captain in the successful 1970s pop musical duo Captain & Tennille, with his wife, Toni Tennille.
He was also a keyboard player with The Beach Boys in the early 1970s, and got his nickname of "The Captain" from the group's lead singer Mike Love. He perpetuated this nickname and image by wearing a nautical captain's hat.
Dragon also made significant contributions with captivating keyboarding and scoring on the Beach Boy's twenty-third official album, their 1972 release Carl And The Passions - "So Tough". Dragon's orchestrations on the tracks "Make It Good" and "Cuddle Up" translated the melodic ideas that Dennis Wilson was looking for."