Garuru

Garuru is an S-rank sniper, the leader of the Garuru Platoon and Giroro's older brother. He's an indigo Keronian frog with a black helmet, has a red triangle pointing downward with a line in the downword middle for his personal symbol and also wears a belt that, unlike Giroro, is kept for power instead of to remember deceased friends during a Keron war. When he heard that the Keroro Platoon had no progress in their mission and that Giroro was not the leader, the Garuru Platoon went to Pekopon to take care of the mission themselves. Garuru defeated his brother in a one-on-one gun match, but was later defeated in a rematch. Thanks to the Keroro Platoon's friendship and united power, the Garuru Platoon was defeated. It was however hinted at strongly that Garuru's true mission was merely to test the abilities of the Keroro Platoon. Garuru and his platoon appear again in episode 130, where he faces a clone of Giroro and in 154 he shows up to aid the Keroro Platoon in defeating ZZZ. It turns out Garuru is the only one who can pronounce this new menace's name without biting his tongue. In the manga he appears in volume 14, where he shocks Giroro by revealing he's there for a short holiday. He brings a gift to Giroro, which grows into a large, flying sweet potato and the brothers have to team up to bring it down, a ploy by their father to teach them a lesson. In the end Powered Natsumi shows up, helping Garuru defeat the potato with her beam sabres as it is immune to guns and such ballistic weapons and Garuru appears impressed by the girl. During said fight with the potato there is a flashback from Giroro and Keroro's childhoood where we see a younger, presumably teenage Garuru defending his younger brother and friend against two bullies intending to take over their secret base/playground. Another interesting detail is that the younger Garuru wears the same kind of belt as present day Giroro, with a rectangular buckle. In volume 15 he sends Pururu to investigate the Keroro Platoon on their desire to invade. Source - Wikipedia