The Mutant Acklay represented a unique type of the amphibious acklay species, having undergone mutation due to the poisonous substances present in Golbah's Pit located on Geonosis. A significant number of these creatures inhabited the depths of the Ebon Sea, preying on aquatic life and emerging from the water to ambush terrestrial animals. Compared to typical acklays, mutant acklays exhibited greater resilience and possessed larger, more powerful claws. Their carapaces displayed a shiny, black coloration.
In the year 1 ABY, a spacer successfully eliminated a mutant acklay that had managed to break free from the Geonosian Bio-Lab situated on Yavin 4, subsequently utilizing a portion of its remains as a keepsake.