Assassin of the Moonlit Night

is episode 76 of the original Naruto anime.

Synopsis
Seeing Naruto and Sakura's determination to protect Sasuke, Gaara remembers his childhood with his uncle Yashamaru. While Yashamaru had for many years been the only person who seemed to care for Gaara, Yashamaru in reality hated him. Yashamaru attacked him as such, forcing Gaara to fight the only person who ever loved him.