Umbreon has bright yellow rings around both ears and tail, as well as on the upper parts, its front and back legs, and one in the center of its forehead. The rings glow when under the influence of moonlight.
Its physical characteristics seem to be feline, with a lithe thin body, cat-like eyes, a short muzzle, and a thick bushy tail. Its origins could be of black cats; its rings also give it an Egyptian like feel, perhaps with roots from Bastet (WereCat). Its ears are rabbit-like, and it shares some traits with the Moon Hare of Japanese folklore.
On the night of a full moon, or when it gets excited, the ring patterns on its body glow yellow. It hides silently in darkness and waits for its foes to make a move. The rings on its body glow when it leaps to attack, striking fear in the hearts of anyone nearby. When agitated, this Pokémon protects itself by spraying poisonous sweat from its pores.