Entei

Entei makes his first appearance in Chapter 294 "Entei" and in episode 141 named Entei the Demon Horse Unleashed. Entei first appears to a rather powerful naginata-wielding ogre demon named Rengokuki who fought off hordes of demons with ease with a strong will. Recognizing his strength, Entei offers him his servitude and the two become a feared duo. Some time later, the demon is pacified by a powerful holy seal which is then destroyed by Hakoudoshi. Entei reunites with his old partner and does battle with Inuyasha's group and is able to fend them off if only for a little while before fleeing. He later comes across Hakudoshi and challenges him, but his seems to be unable to even phase him. As the 'battle' drags out, Entei begins to second-guess Rengokuki's power and eventually throws him off his back, rejecting his old master and accepting Hakudoshi as its new master. The demon is subsquently beheaded and the offspring takes his weapon as a prize. From forward on, Entei is ridden on horseback by Hakudoshi for all of his future appearances until he is finally vanquished by Inuyasha from his Backlash Wave.