Ekans is a purple, serpentine Pokémon. Its eyes, underbelly, the thick stripe around its neck, and rattle are yellow. Ekans has three pairs of black lines encircling its body, as well as another line that connects to each slit-pupiled eye and curves toward its nose. Its large mouth has a round, pink tongue and no visible teeth. While painful, a newborn Ekans's bite is not venomous. This Pokémon grows longer with age.
Ekans lives in grassy savannas and plains, where it moves stealthily through grass. It can also be found in forests and desolate wastelands, where it preys on Eggs from Pidgey and Spearow nests, but will strike other prey from behind. By flicking its tongue out, it is able to detect danger and the scent of prey. Its jaw can detach to swallow large prey, but such a meal can make Ekans too heavy to move or become stuck and cause it to faint. It wraps itself around tree branches at night to rest. If not in a tree, it will coil itself up—a position in which it can defend itself from all directions. In the second movie, it is revealed to possess some swimming abilities. In Generation I, Glare was its signature move.
Evolution
Ekans evolves into .
(Source: Bulbapedia)