Baki

is the sensei of Gaara, Kankuro, and Temari.

Personality
During the Chunin exam, he had confidence in the ability of all of his team members, although he comments on Kankuro not taking the battles seriously enough. He also worries frequently about Gaara's mental stability and his control over Shukaku.

Konoha Invasion
Baki led the fight with the Sand and Sound shinobi in the Konoha stadium during the invasion and had an unfinished duel with Genma.

Baki was also the one who murdered Hayate Gekko after discovering him eavesdropping on a conversation about the plot to destroy Konoha, in order to earn the trust of the Sound Village.

Rescue the Kazekage
He seems to be serving on Suna's advisory council. When Kankuro was injured by Sasori, Baki seemed to be concerned about Kankuro's condition.