A Tyk was a creature that ate light. A Tyk's size depended on how much light it consumed, and it could grow to a phenomenal size.
One Tyk was found on the Moon in 2039, where it had lain dormant in the Shackleton Crater on the dark side of the moon. Awoken by astronauts from Earth in search of water, it was led into a trap before being put in a booster rocket and put into a permanent orbit around the Sun. (COMIC: The Lunar Tyk)