Background information Edit
The costume was a creation by master sculptor Wah Chang and was a reuse from the TV series The Outer Limits, for which both Prohaska and Chang also worked. (Star Trek: The Magazine Volume 3, Issue 9, p. 71) Originally, it was used for the Calco creature in the episode "Fun and Games".
In the scripts for "The Cage", the creature was described as "a flat anthropoid-spider thing" with "ugly fangs". At some point during production, the spider became an ape, and the creature was so described in final credits as an "anthropoid ape".
See also: [[Mugato}}