Gutrot

Gutrot is the Omnitrix's DNA sample of an unknown species from an unknown planet.

Ben as Gutrot
Gutrot has the appearance of a mechanical humanoid in a green outfit, with the exception of his head and shoulders being a bluish-purple color. He has four fingers on each hand, which are apparently gloved. Like Water Hazard, he has nozzles/openings, from which he can eject gas. He has two on both of his arms, one on each of his shoulders, three on the rim in between his shoulders, three on his head, one on his back and one in the center of his posterior. He has a belt with a window on his stomach so that the gas he uses can be seen.

Gutrot wears the Omnitrix symbol on what appears to be some kind of gas mask in front of his mouth.

Nega Ben as Gutrot
Nega Ben's Gutrot looks the same as Prime Ben's but his skin is pink. His eyes are grey, his outfit is pale blue and his Omnitrix symbol is also grey.

Personality
Gutrot has a cynical sense of humor and speaks with a gruff tone. His tone give him a rather tough yet easygoing "wise guy" sort of vibe to him. He is also usually pretty calm and level-headed.

Powers and Abilities
Gutrot's innards contain various gaseous elements, making him a walking chemical laboratory. Gutrot has the ability to make compounds of almost any type and expel them as gas from the various nozzles on his body for both offense and defense.

Such gases include the following: The strength of these gases depends on the amount expelled and their chemical makeup.
 * Sulphur Dioxide
 * Sulphur dioxide is a highly combustible and toxic gas, with a very pungent smell that can be used as a form of tear gas.
 * Nitrous Oxide (commonly known as laughing gas)
 * Laughing gas can be used to incapacitate an opponent by making them laugh uncontrollably.
 * Fluoromethyl-hexafluoroisopropyl-ether (also known as Sevoflurane)
 * Sevoflurane is normally used as an anesthetic, but it is also useful as a knockout gas with short-term memory loss as a side-effect.
 * To'kustar Pheromone
 * This gas can attract a To'kustar, causing it to follow Gutrot where he wishes to direct it.
 * One of the gases he can use has acidic properties.

Gutrot also has a very advanced knowledge of chemistry as well as the effects the gases would do to someone; this knowledge seems to be innate since Ben as Gutrot said not to ask how he knew, indicating that like when he turns into Grey Matter or Brainstorm, he may not fully understand what he is doing from his personal view. Furthermore, he also seems very intelligent in general, as he was discussing the ramifications of time travel with Rook and Spanner, as well as explaining that hitting someone on the head would simply result in a concussion rather than amnesia. Gutrot's use of pheromone gas also demonstrates some degree of biological knowledge, given that he understood a species enough to create a gas that specifically targeted it.

Weaknesses
When Gutrot uses his gas, it makes a large cloud, which is susceptible to prevailing winds. This can endanger innocent bystanders.

Some of Gutrot's gases are flammable, so he must be careful in situations that might ignite them.

Opponents who are effectively shielded are immune to Gutrot's gases, mainly through the use of a gas mask or insulation.

Ben

 * Gutrot made his first appearance in Animo Crackers. Gutrot defeated both Animos.
 * In Weapon XI: Part 2, Gutrot used a pheromone to lure two Way Bads to the Rooter's Base. He later attempted to battle Kevin but was reverted back when Kevin absorbed power from the Omnitrix.
 * In Vreedlemania, Gutrot was used to stop the Krakken, but the Pretty Boy Vreedles stopped it for him.
 * In A New Dawn, Gutrot appeared for a short time when Ben was cycling through his aliens.

Nega Ben

 * In And Then There Were None, Gutrot failed to capture No Watch Ben and was wiped out by the Chronosapien Time Bomb.
 * In And Then There Was Ben, Gutrot was brought back to existence by Clockwork.

Season 5

 * Animo Crackers (first appearance)

Season 6

 * Weapon XI: Part 2

Season 7

 * Vreedlemania

Season 8

 * A New Dawn (cameo)

Season 5

 * And Then There Were None
 * And Then There Was Ben

Etymology
Gutrot's name is a reference to "Rotgut", a name shared by several fictional characters. Rotgut is also a Prohibition-era slang term for homemade alcoholic beverages, in reference to his power to mix chemicals inside himself. "Gut rot" is also a slang for stomachache.

Trivia

 * Gutrot is based on the Pokémon Koffing, which is Derrick J. Wyatt's favorite Pokémon.
 * This makes Gutrot the second alien to resemble or be based on Koffing, the first being Ultimate Gravattack's mini planetoids.
 * Additionally, he bears resemblance to the Sontarans from Doctor Who. Interestingly, the first story to feature the Sontarans since the show's revival in 2005 (The Sontaran Stratagem/The Poison Sky, both 2008) revolved around the Sontarans trying to convert the Earth's atmosphere into clone feed -a poisonous gas to humans.
 * Technically speaking, Ben didn't name Gutrot until the future Animo told him what the alien's name was.
 * Ironically, chemistry is one of Ben's weaker subjects, though Gutrot seems to be an expert on it.