Agent X is a xylophone apparently hired by the O.W.C.A. to work as one of the organization's many secret agents.
Background Information[]
Agent X was the last example in "Secrets from OWCA: The Organization Without a Cool Acronym". Upon realizing that the Agency hired a xylophone, Major Monogram asked, "A xylophone, Carl? Really?" Carl replied, "We didn't have any animals that started with X, sir." Monogram then sighed and remarked, "We pay you too much."
In reality, there are actually animals that start with the letter "X". The X-ray fish, xenops and xoloitzcuintli are some examples, the exclusion of which was likely a choice made for this joke.
This is the second permanent agent that isn't an animal, but rather an object, the first being Planty the Potted Plant. The first would be Norm, if he wasn’t fired shortly after he was hired in “Traffic Cam Caper”.