Aquiles is the general of the Hydrorai Serpentine tribe. She is one of the two female Serpentine in Ninjago, the other being Wetak. Her name has part of the word aqua, another word for water, in it. She lays an egg once every 5 years to add another warrior or scout to the Hydrorai to keep the amount of warriors and scouts high.
When the Ninja went underwater with new air tanks to see if Lloyd had released the Hydrorai, he didn't, but they didn't know that their tomb was in the sunken ship that they found, and the Ninja released them on accident. The Hydrorai attacked, and Aquiles took part in battling Kai. When Samurai X appeared, she beat most of the Hydrorai, forcing Aquiles to call a retreat, and all the Hydrorai went back into the sunken ship.