>>8136115I know what that is!
Sadly, mine’s been gone for like 20 years, so no pics.
It’s an add-on “battle claw” that was included with a Terminator Endoskeleton-style hand. It had pulleys that you put your fingers in to make the robo fingers flex individually or together. The add on clipped to the top and “deployed claws” when a fist was made.
It probably came from KayBee in the mid 90’s, though places like Spencer’s had them too.