Gaius is Gaia's "little brother," a smaller, male and mobile version created by Ghosthande and originally released for the CCSF 2010. He was later re-released with new agents and voice files for the CCSF 2011.
Like Gaia, Gaius can eat gadgets, but is incapable of replenishing the ship's bioenergy (if used with Creatures 3). Gaius is also breedable and hatches from an egg, unlike Gaia, but is capable of movement. It is also safe to splice Gaius with other creatures as it won't crash the game as it often does with Gaia.
The original pack included four agents:
- A robotic butterfly called the Holo-Wing
- The Spigot Plant, a mechanical "plant" that grows in inorganic areas, similar to the Botanoid.
- The Solar Flower, another mechanical "plant" which attracts Holo-Wings
- A spaceship toy that flies around
The expanded pack included an additional three agents:
- A robotic hummingbird called a Whirly, which is attracted to Chyme flowers
- The Chyme plant, which grows fruits other creatures can eat
- The Tumbleslink, a wiry "reed" that turns into a slinky as it decomposes