Sgt. Frog Episode 83: Keroro, Hotspring Murder Case / Kururu, An Irritating Fellow
Episode 83 of 358 of Sgt. Frog, aired November 4, 2005, 25 minutes. Available with English subtitles and dub where released.
Episode summary
There`s a terrible mystery at the hot springs! 556 has fallen down and gotten knocked unconscious, and they have to figure out the perpetrator. And then Kululu`s "If we lived twice" Gun malfunctions, and he gets turned into a baby! Source: crunchyroll