Plastic rocks and fabric monster, my beloved~
My favorite practical effect ever. 😏
The alien mother – called a Horta – was played by stuntman and actor Janos Prohaska using a costume that he created. Indeed, it was Prohaska himself who inspired the story for this episode when, reportedly, he crawled into the Star Trek production offices while wearing a version of it and showed it dropping an egg.
I heard/read another version where he placed a chicken (like, a dead, plucked, ready to cook chicken but I don’t recall whether raw or cooked) on the floor, wriggled the Horta over it, then wriggled away leaving a stripped chicken carcass in its place.
