Amphi-Hydrus

The Amphi-Hydrus were amphibious creatures native to the water-planet Dac. They were small, physically weak creatures but were masters of mind control, using the powers of the dark side of the Force to manipulate others into doing their bidding. Shortly before the subdjugation of the planet by the Galactic Empire, they gained a foothold of the entire planet by telepathically controlling a few rancors which had been imported to the planet. They were seen on the back of these monstrous beasts, riding them and wrecking havoc wherever they went. However, when the Empire attacked, this all came to an end and so the Amphi-Hydrus' simply became swamp dwellers, and bitterly awaited the chance to recapture their previous power.

Behind the scenes
The Amphi-Hydrus was created by Daren Horley, a Star Wars fan, as part of the Design An Alien contest held in the Star Wars Galaxy Magazines. Though the entry was not picked as a winner, it was given an honorable mention in Star Wars Galaxy 7 and so it is not known exactly how canon the creature is.