Saburouta

Saburouta is a character that appears in episode 20. He claim to be courageous man and wanted to kill the demon. But in reality, he's a coward that submitted himself to Nue after being frightened to death of seeing people body parts eaten by the demon. From that day onwards, he even helped the beasts to lure any traveller into its territory and devour them bit by bit.

(Source: Dororo Wiki)

In the original manga Saburota is quite a different character. He's looking to join the samurai on either side of the war. He determines that Daigo's side is stronger and goes to join his side of the war, where he meets and teams up with the horse Midoro.