Geraster is a cold-blooded piscivorous bilateral animal. It has five primary limbs each with an eye and a mouth-like hand, a tail of many reduced limbs, and a jawed mouth full of sharp teeth located below the front-most limb. Its back and head-arm have sails on them.

A version of the creature actually made in Spore is coming eventually; it's probably not possible to make it as a vanilla creation, so it will be modded.

This creature was made as an attempt at the most difficult taxonomy challenge with a correct answer possible. It fits within a real-world class of animals, and it should become obvious which one once one knows why.

This classification challenge was solved by Opdagon, who correctly guessed it was a starfish. Honorable mention: Dinoman972, who I trust was being truthful when he said he had a feeling it was a starfish before. The geraster is essentially a starfish larva that stayed that way and then evolved into a land-dwelling creature.