Zō

There have been several appearances of an unnamed ANBU captain from Konohagakure, wearing white robes and a cat-like mask. It is unknown if this is the same person.

Invasion of Konoha
The ANBU captain and seven other ANBU members were stationed in the Chunin exam arena during the final rounds of the Chunin exam. When Orochimaru launched the Invasion of Konoha, the ANBU captain and his team rushed to help the Third Hokage. However, before they could reach him, the Sound Four put up a barrier and when one of the ANBU touched it, he burst into flames and died, leaving the ANBU captain unable to assist. He and his remaining men were forced to watch the battle between the Third and Orochimaru. In the end, the Third Hokage died due to using the Dead Demon Consuming Seal and Orochimaru stabbing him with the Kusanagi Sword: Long Sword of the Heavens. When Orochimaru retreated, the ANBU captain and his men tried to prevent them from escaping, but Kidomaru prevented them from following with his webs. At the Third Hokage's funeral, the Captain cursed at his inability to help the Hokage, saying "In the end, all we could do was watch".

The Return of Genno
In the Genno filler arc, a similar-looking ANBU captain and his team interrogated Naruto about Genno by using the Time Reversal Technique.

Three-Tails Arrival arc
A similar-looking ANBU captain died at the hands of Kabuto on a mission trying to find the location of one of Orochimaru's hideouts. He then destroyed his body shortly after sending a bird carrier back to Konoha with information about his mission.