Taruru used to be Tamama's apprentice and still refers to him as "master" or "senpai," indicating his superior. Taruru was initially more clumsy than Tamama. He is a blue Keronian tadpole with an orange and yellow raindrop-shaped emblem, symbolizing an "old driver" in Japan. However, he matured faster; by his appearance in volume 10/episode 101, he had developed adult features instead of tadpole ones.
Taruru first appeared to verify the rumors about the Keroro Platoon, revealing what Tamama had told him about them. In the anime, he also made several appearances alongside his childhood friend Karara, forming a duo of mischievous tadpoles. Despite his earlier clumsiness, Taruru became highly skilled during his training with the Garuru Platoon, surpassing Tamama's abilities and defeating him in a face-off. He then captured Momoka and Paul, later capturing Mois as well.
After Keroro motivates his platoon to support Tamama, who gains power from the Super Rhinoceros Beetle, Tamama returns for a rematch and defeats Taruru.
