Voyage to the Bottom of the Sea 4x16

A lobster-like alien emerges from a capsule retrieved from the ocean floor. He claims that all he wants is one of Seaview's nuclear rods to power his ship for the homeward journey, but neither Captain Crane nor Admiral Nelson is convinced he can be trusted. Victor Lundin also played the neck-braced Hansjurg in Season 2's "The Menfish".