Nico

Nico aka Nikora, "The Canis Minor", is a Silver Keys' Celestial Spirit that has no obvious combat abilities and is stated to usually be used as a pet for low-powered Mages. Nikora keys are shown to have been sold for as little as 20,000.

Appearance
Nico is a short, stout green creature with palegreen marks on the back of his head, he has bland eyes and a golden horn-like nose. His body is often shaking nervously, though this doesn't always occur.

Key of the Starry Sky arc
Note: Events in this arc occur only in the anime and do not constitute canon material.

Magic and Abilities
Immortality: As a Celestial Spirit, Nico cannot die, unless he is forced to stay in the Human World somehow.