The Abominable Snowman - S4.E18

"But that's not the goal of a man -- of a scientist!" Admiral Nelson At an experimental station in the Antarctic, the crew discovers a 'tropical paradise' -- but most of the scientists are missing. When two unconscious survivors are brought aboard Seaview, something deadly starts to stalk the corridors. Meanwhile, the temperature outside is still rising .... * The white furry monster costume also appears in at least one Lost in Space episode.