Akamaru Trembles: Gaara's Cruel Strength!

is episode 34 of the original Naruto anime.

Synopsis
As Team 7, Team 10, and Team Guy recover, Team 8 witnesses Gaara mercilessly kill a team of Amegakure genin. Although Gaara prepares to turn his attention to Team 8, his siblings persuade him to leave them alone. Gaara's team shatters the record for reaching the tower, reaching their destination in about an hour and a half, and Gaara does not have so much as a speck of dirt on his clothes.

Trivia

 * In the English dub, Anko says that Gaara is brunette (brown haired), as he is in the manga, but he is really a red head in the anime. This might have been a script malfunction from the manga to anime.