Monty Cross is a minor antagonist of the Myles Bots film and the older brother of Dr. Tadashi Cross.
Myles Bots film
He may have been the best of the best in Pink Diamond's forces but he only served as cannon fodder to show how much of a threat the Myles Bots pose to Pink Diamond's plans. He imprisoned Ono and Bee Miraculous Holder in Diamond Chemicals and placed a chip inside their neck that has the potency to cause their heads to blow up which would kill them. Unfortunately for Cross and Ono, Bee Miraculous Holder break out of their cage and, deactivating their Nanite chips, use Ono's vision to find a power generator whilst Bee Miraculous Holder helps the bird as they ram the evil criminal into the power generator killing him and freeing the two from his manipulative imprisonment. Though Pink Diamond had developed a grudge against Monty's killers, the Myles Bots have been formed thanks to his vengeful actions and were put under the care of 28-year old Zachary Delightful and his partner Carrie Courageous. Worse, he wound up getting his karma after the Myles Bots defeat their henchmen and gang up on the villain. Meanwhile, Airborne turned out to be a team member deep undercover and thus Monty's death was in vain. Later after Pink Diamond unleashed the villains that have been killed previously by the team, Monty joined them laughing evilly only to be defeated by Airborne (really Rocket Raccoon) as he is sent back to the afterlife and became the first revived antagonist to be destroyed once more.