Umbreon is a combination of umbra (Latin for shadow and ghost, as well as the name for the moon's silhouette during a solar eclipse) and eon (an immeasurably long period of time, possibly referring to how long evolution takes naturally). Eon is a suffix all Eevee evolutions share and was Eevee's English prototype name.
Umbreon's origins are uncertain, though it could be based on a black cat or possibly a black fox, a color variation of the red fox. Its long ears also are similar to those of a hare; numerous East Asian legends concern a Moon rabbit. The rings on Umbreon's body look like Egyptian lunar markings and jewelry that have been associated with animal sculptures, such as cat statues of Bastet and statues of the jackal god, Anubis, from Ancient Egypt. They may also be meant to resemble solar eclipses.