Loco

Loco is a member of the Blues and Reds, a group of Simulation Troopers that are very similar to the Reds and Blues of Blood Gulch.

Role in Plot
He and the rest of his team perform terrorist attacks ten months following the Chorus-Charon War, seemingly in vengeance for the UNSC's actions towards Project Freelancer personnel.

Loco was the first member of his team to meet the Reds and Blues face-to-face and instantly took a liking with his counterpart Caboose.

Skills & Abilities
Despite his stupidity, Loco is a surprisingly good engineer and actually knows what he's talking about.

Trivia

 * Loco's name may be short for "Locomotive", an opposite for "Caboose".
 * His name is also Spanish for crazy.
 * Loco appears to possess a talent for engineering; which arguably is a skill that Caboose possesses, albeit apparently to a lesser degree.
 * Loco was apparently raised by wolves. This may account for his poor verbal skills, as children who grow up feral rarely develop beyond basic verbal skills once if ever picked up by social services.
 * Loco's poor social skills, genius engineering abilities, blue armor, and being raised by wolves cause him to bear a superficial resemblance to Billy Cranston of Power Rangers with Billy being the Blue Ranger, eventually having a wolf as his zord, and his beyond genius abilities in mechanical engineering.