Doyakentchi looks like a brown dog with darker ears resembling Doyatchi's hair. He also has similar eyes and the same mouth as Doyatchi.
In the Anime
Tamagotchi! Yume Kira Dream
His name comes from Doya (どや) which is from the name of Doyatchi. The second part of his name may come from yaken (やけん) or kenshu (けんしゅ). Yaken actually means a dog with no owner, but kenshu can mean any type of purebred dog.