(written from a Production point of view)
Janos Prohaska (Hungarian: Prohászka János) (10 October 1919 – 13 March 1974; age 54) was a Hungarian stunt man, actor, and animal imitator. Several of the Star Trek: The Original Series monsters and aliens were performed by Prohaska.
Often nicknamed "The Great Janos", he specialized in performing different out-of-this-world creatures and exotic animals, especially apes. He was employed in numerous television series and feature films during the 1960s and early 1970s. Among others, he worked for the classic science fiction series The Outer Limits; in particular the monster from "The Probe", the last Outer Limits episode, is similar in geometry and movement to the Horta. He also appeared in series such as The Munsters, Lost in Space, Bewitched, I Dream of Jeannie, Gilligan's Island, Voyage to the Bottom of the Sea and Land of the Giants; and movies such as Escape from the Planet of the Apes (1971, with Ricardo Montalban, William Windom, Jason Evers and James B. Sikking). His most famous role was the "Cookie Bear", which he played on The Andy Williams Show between 1969 and 1971.
Prohaska's thick Hungarian accent prevented him from getting speaking roles. A plane crash claimed his life in 1974, while working on the ABC series Up from the Ape (aka Primal Man), which featured Anthony Zerbe.