If it is attacked, Cascoon remains motionless however badly it may be hurt. It does so because if it were to move, its body would be weak upon evolution. This Pokémon will also not forget the pain it endured.
– Pokemon Sapphire Pokedex
Cascoon is one of Wurmple’s evolutions; it evolves into Dustox. In the anime, May’s Wurmple evolved into Silcoon while Jessie’s Wurmple evolved into Cascoon.
Stat-wise, it has Defense as its highest stat, and not much else.