Fire-spider
The fire-spider was an artificially created spider, a type of arachnid arthropod animal lifeform.
The fire-spider was a large hybrid developed by a team of biologists in the year 2266 at Research Satellite-5, a Federation space station. The animal was about the size of a human hand and glowed like a firefly with bioluminescence. It had a two-year life span and ingested only bacteria.
Spock observed that such an animal would be invaluable in a survival kit. (TOS comic: "A Bomb in Time")