K'tl is a being from the fifth dimension who formerly possessed U.S. metahuman Karl Starr.
In 2001, K'tl arrived in Chicago, Illinois, in this dimension by possessing Starr, whose metagene enabled him to subconsciously communicate with the fifth dimension. K'tl killed several people by causing their heads to spontaneously explode before he was taken to a psychiatric hospital. Before his planned release into the custody of the MCCA, he escaped the asylum and traveled into Chicago.
K'tl's good counterpart is M'xy, who possessed another asylum inmate named Mick Harrison.