Roserade is a bipedal Pokémon with an appearance that incorporates features of roses and masquerade attire. It has hair made of white rose petals, and a leafy, green cape with a yellow, collar-like bangle on its neck. The cape pattern reaches toward the back of its head, in spiky, sepal-like extensions on the hair. A male will have a shorter cape than a female. It has a dark-green mask over its red, yellow-lidded eyes. The lower portion of its face is light green, and it holds a bouquet in each hand, with a red in its right hand and blue in its left. Its limbs and underside are light green. Its feet end with yellow tips.

Roserade lures prey with a sweet aroma. The more toxic its poison, the sweeter its aroma becomes. Each hand has different toxins, but both hands can jab with near-deadly power. Roserade's right arm contains poisons that act faster, while its left arm contains poisons that act slower. Regardless, Roserade's poison can be life-threatening. It attacks with a dancer-like elegance and uses hidden whips covered with poisonous thorns.