Luma

From Memory Alpha, the free Star Trek reference

Luma was an Eymorg who lived underground on the planet Sigma Draconis VI.

Luma was encountered by the landing party from the USS Enterprise in 2268 as they attempted to search for Spock's brain. She was startled by their sudden appearance in their underground complex and attempted to stun them, but she was stunned first by Captain Kirk. Kirk then attempted to interrogate her for information, but she was unable to help because she only had the mind of a child. (TOS: "Spock's Brain")

Luma was played by actress Sheila Leighton.