Ultimate Swampfire

Ultimate Swampfire is the ultimate form of Swampfire. His first appearance was in The Final Battle: Part 2, making it Ben's first ultimate transformation, a reference to Ben's transformation to regular Swampfire in Ben 10: Alien Force, being his first transformation when he puts on the Ultimatrix. He appears in Ultimate Alien, as one of Ben's new aliens. He makes his Ultimate Alien debut in Ultimate Aggregor to fight the mind-controlled aliens.

Appearance
After the induced evolution, Swampfire now appears as humanoid tree with three blue gooey shells containing an organic, blue-colored napalm kerosene gel-like solution (as confirmed by Dwayne McDuffie), that Ultimate Swampfire shoots out and ignites blue-colored flames that are nearly three times as hot as regular Swampfire's flames. He is the same size as original Swampfire. He has many of the same abilities. He also has the same feet as Swampfire. He now has a blue Heatblast-like face inside a blue bubble. His body is composed of petrified wood.

Abilities
His pyrokinetic and chlorokinetic abilities are greatly increased, but he cannot regenerate. Instead, he is made out of a lot tougher material (like petrified wood, so it was described) making him more resistant to damage. His speed is also the same as his original form but he makes up for it with his lethal fire bombs that have knocked even Vilgax out cold. Ultimate Swampfire shoots blue flames while Swampfire shoots ordinary-colored fire, these blue flames could arguably be hotter and more powerful, as 'blue' flames are hotter in real-life. He also shoots a huge pyrokinetic beam when he combines his hands together. He also possesses super strength. He probably has the same plant abilities as Swampfire, and is shown to be able to generate a vine from his body to change forms. (By touching the Ultimatrix symbol on his chest.)

Alien Force

 * The Final Battle: Part 2

Ultimate Alien

 * Ultimate Aggregor

Translation

 * Portuguese: Fogo Fátuo Supremo/ Fatuous Fire Supreme
 * Dutch: Ultieme Moerasvuur (Ultieme from Ultimate, Moerasvuur from Swampfire)

Trivia

 * Ultimate Swampfire is in an online Ben 10 3D game called Ultimate Crisis.
 * In a beta Ben 10 action comic cover Ultimate Swampfire appeared to resemble Heatblast, being red, while the kerosene shells were yellow.
 * It has been confirmed, by the Ben 10 Ultimate Alien Cosmic Destruction website, that Ultimate Swampfire cannot regenerate, but is now tougher


 * Swampfire was the first alien Ben used after the Omnitrix recalibrated, as well as Ultimate Swampfire being the first to be used on the Ultimatrix by Ben. Ironically, the first transformation in the first series was Heatblast, making the first alien he uses on the Omnitrix/Ultimatrix after every stage of it's life, a fire related alien.