Agent K (also known as Kay, or simply K) is a fictional MIB agent in the film Men in Black, its sequels Men in Black II and Men in Black 3, and Men in Black: The Series. Agent K is portrayed by Tommy Lee Jones in the three films, by Josh Brolin in 1969 sequences in Men in Black 3, and voiced by Ed O'Ross and later Gregg Berger in the animated series.