Steenee is a bipedal, plant-like Pokémon with a humanoid appearance. Its torso and legs are dark purple, while its hips, arms, and head are all white. It has dark purple eyes with purple, triangular markings over them similar to stylized eyelashes. On top of its head is a large, light green calyx. The calyx has short leaves on the front and back, two large leaves out to the sides similar to pigtails, and a short stem on the top. The right leaf has two yellowish-green spots on it. The upper part of its torso has short ruffles at the top similar to a dress. Its wide hips are made up of six segments and resemble the flesh of a mangosteen. Its slender arms have slightly rounded hands with no visible digits, and its legs have pointed tips.
While it has a delectable fragrance, this Pokémon also has a tomboyish personality that can make it hard to get along with. Its calyx has hardened, allowing it to play with other Pokémon without worrying about being damaged. However, the leaves spin as Steenee moves and often strike nearby objects. It apparently does not care what it hits, and even uses the calyx as a form of attack. Foes are struck with the leaves first, then kicked by one of Steenee's equally hard legs.