Upton Julius is an industrialist and the main antagonist of the Impossible Creatures Campaign. Virtually all other foes in the story take orders from Julius, making him the player's greatest enemy.
Julius plots to take over the world with the power of combined creatures and the Sigma technology, but requires Rex Chance and his unique abilities to assure his victory.
Before the Campaign
Julius appears to be an ex-militant as he wears medals on his chest, often speaks with an authoritative tone and has thorough knowledge of battle strategies. Presumably after retiring from the military, he turned to the world of business and became very rich and influential. He came to own several railroad companies and had connections in all kinds of areas in the industrial world. He also became acquainted with Eric Chanikov and helped him escape the Russian government after the Tunguska disaster. Julius gained ownership of the entire Isla Variatas chain of islands and allowed Chanikov to seek refuge there.
After Chanikov introduced Julius to the miracle of the Sigma technology, the latter got the idea of using it to take over the world, and soon began preparing for it. He hired Whitey Hooten, Velika La Pette, Otis Ganglion and countless Henchmen to help him with his scheme, and spent many years gathering all the resources needed to dominate the planet.
During the Campaign
In 1937, Chanikov confesses about his son Rex and his extraordinary powers, and asks Julius to help him reunite with his child. Julius realises Rex is essential to his plan, and is able to find him with the use of his connections in America. Unfortunately, he captures and kills Chanikov, having outlived his purpose in Julius's eyes. After failing to capture Rex, Julius sends his various underlings after him and Lucy Willing but they are able to defeat them all.
As Rex and Lucy steadily travel towards Isla Tantus, Julius's main base, they eliminate every other establishment they find on the way and so cripple his scheme for world domination. After defeating Dr Ganglion, Lucy is captured by one of Julius's creatures and is held captive in his Lab on Isla Tantus. When Rex arrives to defeat Julius once and for all, Julius ambushes him and attempts to use Sigma technology to control his mind. He underestimates Rex, however, who is able to take control of his creatures and turn them against him. Julius and Ganglion take on Rex in a lengthy final battle, with Rex emerging victorious. While Ganglion's death is seen on-screen, Julius is carried away by a Spitting Cobra\Vulture creature that, in all likelihood, eats him afterwards.
As an ex-militant, Julius is only satisfied if everything goes as he plans. He is willing to go to seemingly any length necessary to get what he needs done, and this is shown by the sheer amount of preparation he went through to achieve his goal of taking over the world. As if in demonstration of this, he barely even worries when his base on Isla Perculsus is destroyed because he has so many more.
His actual reasons for wanting to dominate the planet are vaguely described by Ganglion as "Mostly politics, ecnomics, saving his precious America from the "evil" clutches of communists and fascists everywhere". Whatever Julius's intentions are specifically, he obsesses over them, as Ganglion also mentions he frequently drones on about them to him. His obsession may be complementary to his somewhat deranged belief that the world depends on his success, and that in taking over it he would save it from the grasp of evil.
Like many of his underlings, Julius has little to no regard for the value of human life. He allowed Velika and Ganglion to experiment on villagers, knowing perfectly well that they could not successfully combine humans. On that subject, Julius exerted huge amounts of effort and resources attempting to capture Rex, the only combined human in the world, simply to kill him afterwards. Julius only cares for things and people for as long as they are useful to him; once they have served their purpose, he will toss them away like waste, with the murder of Rex's father being the best example of this.
In combined creature battles, Julius's style reflects his industrialist nature; he takes all the resource sites he can possibly get his hands on for complete domination of the battlefield. This facilitates his premade army in the game, which consists of powerful but expensive creatures.
Julius's Lab in the game differs from its appearance in the cinematic movies. In the cinematics, it appears to have a Creature Chamber built into it and its surroundings do not resemble Isla Tantus at all.