Originally, she was an extremely huge sentient sunflower with purple petals around the face, which is just a mouth with sharp teeth, two huge leaves behind her head, she also has vines to be used as hands. Now she resembles a human child with blue eyes and light green hair with a flower on top with light pink petals. In the anime, she only has two long toes on each of her feet. In the manga and To Love Ru Darkness, her feet appear more like those of human babies.
In a side story of the To Love-Ru Darkness Manga Series, Celine became older with the effect of the moonlight in a full moon. As seen at the last page of the latest bangaihen series, the effect only last for the night of the full moon.