Entei

Entei is a yokai horse that obeys only the most powerful yokai. Entei makes his first appearance in episode 141 named "Entei the Demon Horse Unleashed." In the very next episoded Hakudōshi tames Entei.

Powers
Speed: In later episodes the Entei's speed is relieved to be much faster than Inuyasha's.

Fire: Entei has the ablitiy to breath fire and his hooves are seen lit in fire primarily when he is floating in the air.

Name
It may have not been mentioned, but this uses the excact name and spelling of the Satoshi Tajiri's legendary pokemon Entei of the popular franchise "Pokemon" of the 3rd movie. This is very simaler to the problem of the popular anime/manga character named Mr. Popo from Akira Toriyama's Dragon Ball, Dragon Ball Z, and Dragon Ball GT with the human shape pokemon Jinx.