Adeleine wears a red beret, green collared smock, blue knee-high socks, brown shoes with yellow laces, a short grey skirt, has black eyes, (green in gameplay) and short black hair.
Adeleine first appears in the second stage of the first world, Planet Popstar. She is simply painting a picture when a Crystal Shard falls next to her. She turns and picks it up, when a Dark Matter materializes on her easel and possesses her. Kirby, Ribbon, and Waddle Dee then arrive to find her possessed, and are forced to battle her. Adeleine summons various monsters from Kirby's past, much like Ado, her counterpart in Kirby's Dream Land 3 as well as a mass of pixels and an unidentifiable, Gordo-esque enemy. Unlike Ado, whose paintings can't be inhaled, only 2 out of 10 of Adeleine's paintings can't be inhaled. The only thing that changes in Adeleine's possessed form is her eyes. Adeleine has bigger eyes when possessed, and has a different iris colour. After Kirby and the gang defeat Adeleine, she agrees to join their team and the three set out to find the rest of the Crystal Shards.
Throughout various levels of the game, Adeleine will appear and paint items for Kirby. If Kirby enters the area Adeleine is in with full life, she paints a 1UP, otherwise she paints a Maxim Tomato. She may also paint pictures to help Kirby solve puzzles so he can obtain a shard.