Character

Keroro is a sergeant of the army of planet Keron, and the leader of the Keroro Platoon. His self-introduction at this time is The Gamma Planetary System, the 58th Planet, Space Invasion Army Special Tactics Platoon Leader, Sergeant Keroro (ガマ星雲第58番惑星 宇宙侵攻軍特殊先行工作部隊隊長 ケロロ軍曹, Gama Seiun Dai Gojuuhachiban Wakusei- Uchuu Shinkougun Tokushu Senkou Kousaku Butai Taichou- Keroro Gunsou). His partner is Fuyuki Hinata. 

Statistics

His blood type is O. Watanabe has stated that he played Keroro as someone who was about 45 years old. Keroro described himself to be a child when Nintendo started selling the Game & Watch systems in Volume 7, Chapter 56^[2]. His body fat percentage is 30%^[3]. 

Etymology

Keroro's name comes from the Japanese onomatopoeia for the sound a frog makes: "kerokero" (ケロケロ, "kerokero").