The giant dry-worm was a creature native to the planet Antos IV. It was capable of generating and controlling energy without causing harm to itself.

In 2267, Pavel Chekov drew an analogy comparing the abilities of the creature identified as the Greek god Apollo of Pollux IV to the giant dry-worm, Earth's electric eel, and another creature he was unable to complete the name of before Leonard McCoy interrupted him. (TOS: "Who Mourns for Adonais?")