Light vs. Dark: The Two Faces of Gaara

is episode 77 of the original Naruto anime.

Synopsis
As Gaara continues to reminisce about Yashamaru, he remembers Yashamaru's defeat and attempted suicide bombing. Although Gaara was able to survive the blast, he lost the only person who ever cared for him. From that point on, Gaara came to love, and care about only himself and starting living off of killing others. Returning to the present day, Gaara quickly restrains Sakura with a claw made of sand and slowly squeezes her. Determined to save Sasuke and Sakura at all costs, Naruto takes Gaara on.

es:La luz contra la oscuridad: Las dos caras de Gaara