It evolves from Helioptile when exposed to a Sun Stone.
Heliolisk is a yellow lizard-like Pokémon. Compared to its pre-evolution, Heliolisk's tail now has an orange stripe in addition to the black tip; there are also orange bands with a zigzag pattern on Heliolisk's hind legs. Heliolisk's head is completely black except for its yellow lower-jaw. It also has two points over its eyes, which contain blue irises. The two frills that this Pokémon had on the sides of its head as a Helioptile are replaced by an orange frilled collar around its neck. A single Heliolisk can generate sufficient electricity to power a skyscraper, simply by flaring open their frills. Heliolisk can use this electric energy to stimulates its muscles, boosting the strength in its legs and therefore enabling it to run 100 yards in five seconds, or about 20 yards per second.