Maltz is a supporting antagonist of Star Trek III: The Search for Spock.
He was portrayed by John Larroquette.
Maltz is a Klingon officer serving aboard Commander Kruge's Bird-of-Prey. Unlike many other Klingons, he was very soft-spoken and seemed to appreciate the scientific aspects of Genesis rather than its military applications, despite hailing from a warrior culture. He went with Kruge to the Genesis Planet, and was the only Klingon to survive the events that took place there. When Kruge beamed down to the planet's surface to fight Kirk, he ordered Maltz to beam the capture Enterprise crew up to the Klingon ship. After Kirk defeated Kruge, he imitated the order to beam up using a Klingon commincator. When Kirg, along with Spock, was beamed aboard, he found Maltz holding Scotty, McCoy, Sulu and Chekhov at gunpoint, and Maltz, realizing he was outnumbered and that his leader was dead, surrendered, telling Kirk he didn't deserve to live. Although Kirk told Maltz he'd kill him, he instead had him locked up.
It was at first believed that Maltz had ritualistically committed suicide for his failure.
However Maltz had survived as a prisoner of the Federation. He was able to provide invaluable assistance to Federation linguists in increasing their understanding of the Klingon language.
Maltz eventually returned to the Klingon Empire. For many years he felt a great deal of shame over his defeat at the hands of then Admiral Kirk. He emerged in 2376 to help counter the Genesis Wave that was devastating the Alpha Quadrant.
Come here, woman. Death is not to be feared. It's an old friend who has waited patiently for us.
~ Maltz to Carol Marcus before their deaths.
Eventually Maltz met Carol Marcus, the mother of the same David Marcus Kruge had murdered nearly a century earlier. Learning that the moss beings were about to launch a new Genesis Wave Maltz and Marcus activated a self destruct device on the space station they were on. Maltz held Marcus in his arms as the station exploded. Due to their sacrifice the knowledge to recreate the Genesis Wave died with them.