Gedd

The Gedds are blue simian-like creatures native to the same planet as the Yeerks; and provided the original hosts for the symbiotic Yeerks to inhabit.

Biology
Gedds are a peculiar species of quasi-bipedal mammalians with yellow eyes, tridactyl hands and webbed feet. They're not particularly gifted as a species, as their intellect, motor skills and eyesight are all comparatively lacking. Besides that, they're plagued by an unusual asymmetry in which one of their legs is longer than the other; resulting in that, despite being built as bipeds, they can't actually balance themselves without keeping at least one of their long arms on the ground.

Culture and society
Due to the difficulties faced from their below-average senses and motor functions, Gedds benefited from a symbiotic relationship with the Yeerks, who helped them to survive in exchange for mobility, as a Yeerk can only leave its aquatic environment while linked to a host. Unfortunately, after first contact with the Andalites resulted in acquiring space-faring technology, the Yeerks turned into an expansionist hostile state and the Gedds were relegated to just one among numerous species of enslaved hosts; usually employed by young and inexperienced Yeerks before they can move on to more efficient bodies.