Tamasaburo is an executive of the Hyaku Monogatari Clan who was created from Sanmoto Gorozaemon's facial skin. He is able to change his appearance and entire body structure to that of someone else. During the game of "tag" in Tokyo, he poses as a shopkeeper and stabs Hoko from behind when the latter lets his guard down.
Despite his appearance, he can be very harsh toward others - regardless of their being friend or foe. He is an excellent actor and is able to adopt the mannerisms of just about anyone, though his degree of success is determined by how much information he has on the target.
(Source: Nurarihyon no Mago Wikia)