Get ready, fight fans! The ultimate warrior is coming at you live from the Milky Way: the Champion of the Universe! He’ll take on Earth’s greatest gladiators with the planet itself hanging in the balance. In Earth’s corner: the jaw-breaking Juggernaut, daring Doc Samson, the ever-lovin’, blue-eyed Thing, and that jade giant, that green goliath...the Incredible Hulk! Are you ready to ruuuumble?!
Bruce Banner and Rick Jones have taken low-key jobs in Porto Verde, Brazil. The boss, Mr. Cabral, is angry about monkey being lose in the factory and starts a fight with Bruce. Of course Bruce transforms into the Hulk.
Just as the Hulk makes his appearance, he disappears. He, Rick, and Monkey have been teleported to a arena where they face the Champion of The Universe (Tryco Slatterus), wielder of the Infinity Gem of Power. The Champion declares that unless a hero from a given planet beats him, he'll destroy that planet.
After a couple blows from the Hulk, the Champion transforms him back into Banner and sends him out of the ring. Juggernaut, Doc Samson, and the Thing each take a turn in the ring and are quickly defeated.
Bruce and Rick watching notice the Infinity Gem the Champion is wearing and figure that if they can get that away from him, he may be defeated.
After beating Earth's heroes, the Champion stomps off tho destroy the Earth. Before he can press the button, Rick offers Bruce Banner as Earth's last hero.
Just as the Champion is about to make mince-meat of Bruce, Monkey grabs the Infinity Gem and gives it to Bruce. As Banner falls from one of the Champion's blows, he attaches the Gem to his forehead and changes into the Hulk again. The Hulk rises, "Hulk know kung fu!". He summarily whoops the Champion's tail.
The Champion loses and agrees to send the Earthlings home. Rick has snagged the Infinity Gem of Power and gives it to the Thing for safe keeping.
An episode of Mini Marvels is included at the end of the book.
4 Skrulls have been ordered to go to Earth and impersonate the Fantastic Four. They agree to practice changing into the likenesses of the 4 different members. Each Skrull changes and... each one looks like the Thing. "I think we have to draw names out of a hat."