Monstrox (Voiced by Mark Oliver) is the main antagonist of the Nexo Knights TV show and is a lead member of the Villain Army.
Monstroy was summoned by Lord Vortech, along with many other Lego villains. He soon become a leader and conforted the heroes whey they arrived at Foundation Prime. Monstrox and the other villains were about to defeat the heroes, when X-PO opened a portal which brought the heroes back to Vorton. Monstrox was present when other villains arrived, standing between Pythor and Lord Vampyre.
Despite the fact that he is weaker than most of the leaders, such as Lord Vortech or the Overlord he is stronger than other members such as Lord Vampyre or Lord Buisness.
He may have the ability to shapeshift, as he transformed himself into a cloud after he was defeated in Season 2 of Nexo Knights.
He is in his human/necromancer form in the Lego Crossover.
He is voiced by Mark Oliver who also voices Lord/Sensei Garmadon from Ninjago.
It's unknown if he is immortal or not. He might be immortal as shown in the end of every season of Nexo Knights, he survived his defeat.