Titannus first encountered a small assembly of Earth's superheroes after laying waste to a large portion of Tokyo. Doctor Strange lead Spider-Man, Nova, Carol Danvers, She-Hulk and Hulk who were all teleported to Japan to investigate and quash Titannus and his rampaging. They met up with Wolverine, who was already in Tokyo and waited for the right time to strike. After a short confrontation and defeating the Hulk with ease, the group decided to hear him out, only to be regaled with a fabricated summary of the past leading up to the current situation.
Titannus had been monitoring the super-hero community for months, hoping to recruit some powerful allies and return to the Trellion Empire to siege a cure for the "poisoned" Princess Amissa that could only be found on her homeworld. Unmoved by Titannus' story, the heroes resume their battle with Titannus, while Doctor Strange and Nova located the wrecked ship and rescued Princess Amissa from her stasis pod. Meanwhile Titannus was making short work of the heroes, and broke She-Hulk's arm. Shortly after their departure, Nova and Doctor Strange returned with Amissa. It was revealed that Titannus was insane, and had fabricated his story. The heartbroken villain committed suicide by crushing his own head, thus ending the battle.
Later, Spider-Man and Wolverine discovered the truth about Titannus and the "Titannus Wars" from an alternate reality version of Tony Stark imprisoned on a SHIELD carrier. Apparently Titannus was still alive, as he possessed the faculty to regrow his own head.
Powers & Abilities
This is essentially, the source or Titannus's powers. Through this process Titannus was able to transform from an average Skrull into a large, powerful being of incredible strength and power. As a normal Skrull, Titannus possesses the same normal standards of his species. He was chosen for this program because he was deemed worthy by his superiors, as the comic shows him defeated another Skrull in combat. Though when he told his story, everything he says contradicts what is happening in the flashback.
One of Titannus's greatest powers is his raw strength as he was able to quickly defeat an enraged Savage Hulk with just a knee to the stomach and two blows to the face. This shows he is able to easily lift over 100 tons. The second time Titannus faced the Hulk he was able to physically overpower him in combat and defeat him once again. Other feats include defeating Wolverine with one punch to the gut, and breaking She-Hulk's arm. In the end, the only thing that proved capable of killing Titannus was his own strength, as he killed himself by crushing his own head.
Gamma Radiation Absorption
During his second fight with the Hulk, Titannus pinned Hulk on the ground and he said to Hulk "You can't feel yourself weakening?! You fool! My armor is fueled by many things--including gamma radiation! I might as well be wrestling a battery!!"
- Titannus appears as a villain in the video game Marvel: Ultimate Alliance voiced by David Sobolov. The heroes meet Titannus while attempting to save the Skrull world from Galactus. He tries to kill the Skrull scientists for forcing him to join the Super Skrull program.