Helioskrills are predatory creatures that live on Sanghelios. In order to feed themselves, they remain completely still at a location, imitating a rock, waiting for unsuspecting prey to pass by. They are thought to be bird-like, as the book The Cole Protocol describes them as living in high, mountainous, rocky places. There is a Sangheili stance modeled on the Helioskrill's hunting position. The performer appears to be resting, but is ready to spring to their feet in a matter of less than a second. The user must have a certain amount of stamina, however, because it can cause the muscles in their legs to begin to burn. Thel 'Vadamee used this position whilst being held in a cell by humans in the Rubble with three other SpecOps Elites.