Alfred Ryder played Professor Robert Crater, the archaeologist who shelters the last salt-eating creature of planet M-113, in The Man Trap, the first Star Trek episode broadcast.
Alfred Ryder (1916–1995) was an American stage actor and director who appeared widely in television drama. He was the principal guest star of The Man Trap, which opened the series on American television in September 1966.
Crater has spent years excavating the ruins of M-113 with his wife Nancy. He is hostile to the visiting landing party and asks only for salt tablets. The truth is that Nancy was killed long ago by the planet's last native creature, which can assume any appearance, and Crater has protected it ever since out of loneliness and pity.
Stunned by Kirk's phaser, he finally admits what he knows. He is killed by the creature aboard the Enterprise before he can identify its current disguise.