Swampfire reappears in the same episode on the morning of Ben's last day of school - in an excited rush, Ben uses Swampfire to cook his food and later avoids his mother's request of making food for her in the same fashion.
Ben uses Swampfire to pursue British antiquities thieves Percy Lancaster and Simon Williams in "The Legacy Artifact". The robbers use grenades to tear Swampfire apart and slow down his regeneration process - Swampfire goes ultimate to chase them down and defeat them.
First, the volume of Ben's muscles increases and causes his muscles to bulge. This followed by the change in shape of his skull and feet. Slime, chlorophyll and various other liquid chemicals drench his bones. His veins begin to twist even further and toughen to become roots; water, chlorophyll and plant chemicals mix with his blood. The blood in his wrists and hands is mixed with a corrosive material. Ben's skin rots, tears and toughens, becoming rotten wood, and breaks and gaps in his limbs show moss growth rapidly forming underneath. Roots creep up and through his body to his neck, where his hair falls off and flowers rapidly grow to form his head shape. Seeds, insects, soil and other garden waste line his throat and cover his face. Certain veins glow green and lead over to a glowing core inside his chest - the core creates a green glow at the center of his chest that brightens before tearing his chest open and planting the Ultimatrix symbol.
Swampfire's appearance in the show follows the same design as Alien Force/Ultimate Alien, but due to the show's imagined CGI animation style and realistic nature, his physical features and anatomy are more defined.
Swampfire's added physical traits reinforce his plant-based anatomy as well as his "rotten foliage" inspiration in the original show - the red and yellow around his head are in fact a mass of flower petals - the color is a bit faded and his entire body is covered in dust - no colors are too vibrant, to further reinforce the fact that he is made of dead plants.
Swampfire's dark face is his skin layered by hardened soil, and small roots and bugs are constantly growing and moving around. His voice matches Dee Bradley Baker's original interpretation, but it comes with a very raspy, scratchy sound to show that cockroaches and plants are lining his throat.
Swampfire's limbs and torso are perhaps the most defined. His skin is tough and slightly rubbery, like rotten wood - the softer parts are visibly dampened by green, dirty water and his limbs now have the addition of large, exposed gaps and cracks, like a real tree. Moss and small roots and branches grow inside and his veins, comprised of roots and transparent tubes flowing with bright green chlorophyll and Ultimatrix energy, are also visible inside these gaps. His rotten bark skin is overlapped by dried-up leaves, grass, dead flower petals, and dead roots that hang freely around his limbs.
His darkened hips and side-torso areas from the show are also made of packed soil, but more moss is visible - some of the spongy material is brown as though it were dampened by muddy water. Roots creep out from the cracks in his skin, and the most roots are visible in his legs, whose black "sockets" from the show look more like packed grass sod.
Swampfire's wrists have much more dry leaves and dead, burned plants to show that his hands conjure fire. His hands bellow a bit of smoke and roots lining his hands are shown retracting to his forearms before a fire ignites. These intricate processes still happen within a second, but they're all still gradually visible because Swampfire's body is practically a semi-dead ecosystem.
Behavior and Abilities
Swampfire's abilities are largely unchanged as the show follows the canon of the first three series. His strength is still enhanced and his combat abilities make him one of Ben's most powerful aliens. His tough tree skin makes for harder impact from melee attacks, and his agility remains high.
Swampfire's fire abilities are again comprised of the same capabilities, with the only changes being visual/aesthetic. His skin and roots on his hands/wrists simply rot, burn, and/or retract upon fire ignition. The fire itself is manipulated at Ben's will, but the smoke sometimes has traces of green in it and is a bit more steamy-looking to show the methane components. Swampfire can also engage in temporary flight or enhanced leaping upon propulsion of fire.
Swampfire's body, as mentioned before, is practically an ecosystem, and bugs, plants and seeds are constantly living and rapidly growing on the spot. This eliminates the need to wait for a seed to appear in Swampfire's body as masses of them, like bodily cells, generate in almost every corner of his body. The seeds themselves are not abnormally large to fit the massive plants Swampfire is known to grow, but the plants themselves have a lot of visible roots and foliage overgrowth that rapidly forms and intertwines and the plants move and attack depending on what Ben chooses to do with them.
Swampfire's regeneration is the one aspect of his abilities the show takes new directions in defining. Aesthetically, when his limbs are severed, slimy goo slightly drips from the serration point in his tree-bark skin - moss pieces fall off and twigs and branches stretch and snap, just like when a regular plant is yanked at. These leaves and twigs hang loose from the rest of his body before roots and vines start twisting their way out of the severed limbs and reconnect with the remainder of Swampfire's body.
Physically, however, his regeneration process is shown to have the disadvantage of slowing down when new plant growth is suppressed upon the death of the plants. The first example of this is in "The Legacy Artifact", where gangsters Percy Lancaster and Simon Williams used grenades to blow apart parts of Swampfire's limbs, then used smoke bombs to kill the growing plants and force them to regrow while under harm. The smoke bombs were thrown so they would get lodged inside the wound and release the smoke, which would kill the growing plants and thus, the limbs.
Ultimate Swampfire is Swampfire's evolved form.
Ben first uses Ultimate Swampfire in "The Legacy Artifact" to pursue British robbers Percy Lancaster and Simon Williams after they use smoke grenades to slow Swampfire's healing process and hold him back. Ultimate Swampfire uses his explosive capabilities to overpower the gangsters and corner them down near a pond, finally defeating them.
From Swampfire (see the Physical Appearance section above to see Swampfire's anatomy in the show), his cracked and broken parts in his rotten tree skin begin to fix themselves as moss falls off and plants and vines inside detract and burn up. The damp and slimy dead tree skin dries and toughens, as his inner muscles bulge and dead plant waste from his body fall off or burn up.
Transitioning now into his ultimate form, Swampfire's back tears open and green veins inside glow - a blue gas sprays out and creates a cloud of blue smoke, which surrounds itself with a bubble and the smoke liquefies into kerosene, and parts of it become jelleyed and thus, napalm. The same process happens to Swampfire's head, which borders itself with tree branch growths. The veins in his body then glow as the dead plant matter inside him is implied to be eliminated, and the veins then glow green as the Ultimatrix symbol extends four spikes.
This transformation happens in roughly five to ten seconds - Alien Force or Ultimate Alien never specified how long a transformation took but it is assumed that when processes are shown, they are slowed-down footage of what happens inside within the flash of a second the transformation actually takes place, externally, during a quicker scene.
Ultimate Swampfire's appearance is again largely unchanged from Ultimate Alien - his anatomical traits are slightly simplified and because of his armor reinforcements, exposed sections of his anatomy are unnecessary when even the original inspiration never relied on a "dead plant" basis, as opposed to his devolved form.
All that is further defined is the dryness of his toughened tree skin, which simply contains rather wide and light indentations and contains occasional patches of dust and dryness. His wrists are in fact shown to be externally scorched as well, as the kerosene and napalm is at its highest potency at his hands, where it ignites and is put into use.
Ultimate Swampfire's bubbles of kerosene are perhaps the largest aesthetic enhancement - the liquid inside is shown to be boiling and steaming - the external bubbles appear a bit slimy. When they "melt" above the boiling kerosene and napalm, they are shown to slightly drip before the shell quickly cools and hardens. It still is barely noticeable and the bubble shells are still simply "transparent and round" upon immediate sight.
Behavior and Abilities
Ultimate Swampfire's abilities, like the show, are simply enhancements and aesthetic changes to the original Swampfire's abilities and as expected, remain largely unchanged. Aesthetically, when he charges up an attack, the kerosene and napalm stored in the large bubble in his back is shown to boil vigorously as small quantities of it flow to Ultimate Swampfire's wrists. His arms' veins glow blue to signify this.
When he propels fire, Ultimate Swampfire's hands have a hole in them that glows and releases a powerful blast of kerosene/napalm-fueled heat, which looks like a midair explosion as it's jetted out and takes violent effect on the target.
This being among his enhanced abilities, non-aesthetically the list comprises of further strength and durability, and added explosive properties to his fire manipulation. Limb regeneration is not necessary when his skin is practically indestructible. It cushions every blow and its softer parts feel like well-inflated tires.
- Swampfire is the first alien Ben uses in the show.
- Swampfire is the first alien Ben uses indoors.