(written from a Production point of view)
Brett Baxter Clark (oft credited as either Brett Clark or Brett Baxter) is an actor who appeared as one of Khan's crewmen in Star Trek II: The Wrath of Khan. His costume was sold off on the It's A Wrap! sale and auction on eBay. 
Some films he appeared in with other Star Trek alumni include Night Shift (1982, with Clint Howard, Gina Hecht, Vincent Schiavelli, Jack Perkins, and Jeanne Mori) and Bachelor Party (1984, with Coleen Maloney, Arlee Reed, Ben Slack, Gerard Prendergast, Jim Hudson, and John Bloom). He also played the role of "Chet" in "General Hospital" (1988).