X (金属アーム) is a tadole keronian that grew up around the time that the Keroro Platoon stared. X's symbol is an X with a circle in it. He is a blue keronian with red eyes and black pupils.

X is a special keronian because he can manipulate anything. He grew up around all girls. So, he decided to make a boy for himself to play with. He told all DNA from all boy keronians to form a mass, and he named it kuma. Kuma was very tall and heavy, so X told kuma to destroy the school he was going to.

X defeated Keroro and killed him. Afterwards, he told kuma tokill himself because he didnt like kuma anymore. Kuma didnt obey, so X had to destroy him by himself. After kuma had died all the DNA went back to all of the keronians.

X had no friends at all, until he met Garuru. He only wanted to be friends with Garuru so that Garuru would give him his belt. X beat up Garuru and took his belt. Garuru escaped X. X had to kill Garuru before Garuru's father heard about it. X found Garuru and killed him. X met Flarere and Mitata and they became best friends after they battled. Mitata had won. They took Kururu's base and they claimed it as the X-base. After that, Mitata , Flarere, and X found a TV and they kept it. X loved TV. Mitata stayed in his holo-training room. While Flarere read books about engineering. Eventually, X's TV had a mysterious face appear on it. Mitata's training room had been hacked too. They tracked the signal back to a young hacker named Kerara. Kerara had defeated them. They all made a pact and they became the X-Platoon. They were Galaxy Destroyers. They thrived off of the destruction of their enemies.