As a primary communications officer for the fort, he is frequently seen toting a large radio transmitter or wired communications pack on his back while in transit and is often put in charge of relaying information and orders to Briggs troops in combat.
Karley is first seen participating in Captain Buccaneer's mission to rescue the lost search party inside the tunnel created by the Homunculus Sloth and later appears as the head of communications during Major General Armstrong's role in the capture of Central Command.
- His English voice actor, Jason Liebrecht, also voiced Alfons Heiderich in the Fullmetal Alchemist the Movie: Conqueror of Shamballa.
- The English credits misspelled his name twice as Carly and Curly.
- He is one of the few minor characters to have his own intermission screen (episode 55).