Callistonian

Callistonians are a race of intelligent amphibious aliens native to Callisto, one of Jupiter's moons. They possess gills that allow them to survive in water indefinitely. However, they can only manage to breathe on land for an hour due to the toxic atmosphere of Callisto. They as a race specialize in chemical warfare and utilized their skills against the Ken during the siege on their planet.

They are the newer, Phase 3 equivalent to the Lexiconians.

History
Callistonains are one of the more recent Jupitarian aliens, native to the moon Callisto. Their planet was the last to be attacked by the Ken during the Ken's war against the Republic of Jupiter, and as such, they had lost all outside military support. Trapped within their own planet, the Ken army scourged their populace with ease, leaving few survivors. The captives were then experimented on shortly after the battle.