Swampfire

Swampfire is the Omnitrix's DNA sample of a Methanosian from the planet Methanos.

Ben as Swampfire
Swampfire is a humanoid, plant-like alien that has an overall green and black colored body, mostly with a flame-patterned head and root-like feet, seemingly holding rocks. Also, his shoulders and head have red petals. Swampfire is taller than an average human and has a distinct rotten stench that worsens with heat. His voice is very stuffy and nasally because he has no nose. Swampfire wears the Omnitrix/Ultimatrix symbol on his chest.

In Ben 10 Omniverse 2, Swampfire's first design is similar to his Alien Force/Ultimate Alien appearance, except for having five fingers on his hands. Swampfire's skin is now olive green, and his arms are larger. The red petals on his shoulder, along with the green thorns on his body, are thinner and longer. His torso design has changed, splitting the black parts on his waist into two. The Omnitrix symbol has also moved from his chest to his stomach.

As of Charmed, I'm Sure, Swampfire's second appearance, or "blossomed"/"matured" form, is plant-like, but with major changes. He looks more muscular and taller. His skin color is now light green. His face is now colored yellow, red, and orange. His pupils are gone. His chin is more visible. His hands are now colored black, with four yellow claws and a yellow hole to unleashed his fire powers. He has six red horns with yellow spots (aesthetically resembling flames); two on each forearm, and one on each shoulder; as well as a green horn on each foot, knee, and elbow. He now has a large collar raised up around his neck. The Omnitrix symbol is still on his stomach.

Powers and Abilities
Swampfire has the ability to ignite methane in his palms, (from yellow holes in his "blossomed" form,) similar to a flamethrower.

Swampfire is also capable of limited flight through means of launching fire from his palms as jet propulsion, as shown in War of the Worlds: Part 1.

Swampfire has a high degree of chlorokinesis. Swampfire is able to manipulate his biological agriculture to stretch his limbs for multiple purposes, as demonstrated in Vengeance of Vilgax: Part 2 and Ghost Town. He can also reattach detached body parts by manipulating his vine-like "veins" to reach out and meld with the insides of the detached limb. Due to his plant-like composition, he is also capable of regenerating at an astonishingly quick pace.

Swampfire's methane can make the Incurseans unconscious. As displayed by Negative Swampfire in The Final Battle: Part 1, by spraying methane at a human's face, it will render them unconscious. Swampfire's methane can also bring plants to life, as shown in Everybody Talks About the Weather, while fighting DNAliens.

In Ben 10: Alien Force (Video Game), Swampfire could emit methane which causes plants to grow over enemies, channel his flames into a concentrated fireball, having the ability to tunnel underground, and immerse himself in a coat of flames. He is also capable of firing a straight beam of concentrated fire.

In [Ben 10 Alien Force: Vilgax Attacks, Swampfire could ignite his hands for "flaming fists", create a ring of fire to attack enemies, and cause thorny vines to sprout from the ground.

In Charmed, I'm Sure, Swampfire's "blossomed" form revealed that he has complete control over the Mutant Pumpkins from Anur Transyl. His fire blast also appears to be more powerful than before. He can grow plants from the ground simply by raising his hand into the air.

Swampfire has enhanced strength, being able to push over a Highbreed Weather Array, as well as hold his own against Vilgax with his bare fists. In his "blossomed" form, he appears to be even stronger and more durable than before.

In X = Ben + 2, Swampfire was able to walk straight through an iron bar of his holding cell.

in Weapon XI: Part 2, Swampfire was shown able to grow vines with a flame tip from his hands and use them as whips.

Weaknesses
In Vengeance of Vilgax: Part 2, Swampfire was continuously cut up by Goop's Anti-Gravity Projector, preventing him from regenerating.

Swampfire can be frozen, shown when a DNAlien froze him in Everybody Talks About the Weather. He can thaw himself out by igniting the methane in the palms of his hands.

According to himself, Swampfire cannot control weeds, though after 'blossoming,' he gains the ability to command the hordes of Mutant Pumpkins.

Swampfire's swampy stench makes it hard to hide from anybody or anything capable of smelling.

As shown in Catch a Falling Star, if Ben turns into Swampfire with a broken arm, Swampfire's arm will be twisted and shriveled. He was also in pain from it.

Ben 10: Alien Force (Video Game)

 * Swampfire is a playable alien character in this game.

Ben 10 Alien Force: Vilgax Attacks

 * Swampfire is a playable alien character in Vilgax Attacks. His fire can be used to burn roots, gas, and enemies.

Ben 10 Alien Force: The Rise of Hex

 * Swampfire is a playable alien character in this game.

Ben 10 Ultimate Alien: Cosmic Destruction
Swampfire can ignite methane in his palms to project fire. His fire is able to destroy a car. Swampfire can double jump by launching fire from his palms as jet propulsion. He is able to create plants and ignite them.

Swampfire looks just like the Swampfire in Alien Force and Ultimate Alien.

Ben 10: Galactic Racing

 * Swampfire is a playable racer in this game on all platforms (except DS).

Ben 10 Omniverse 2

 * Swampfire is a playable alien character in the game.