What is he?

Upchuck is a Ben 10 alien, specifically one of the Gourmand species who inhabit the planet Peptos 12. The Gourmands have a great affinity for food (mentioned: steak, cookies, and Frosties), having the ability to eat anything, food or not, storing it in their shared stomach and then being able to shoot it out as energy beams. The Gourmands have two distinct species, the Perks and the Murks named after their designers Tom Perkins and Glen Murakami. They seem to be inspired by frogs and/or lizards having long tongues they can shoot out and having things that look like gills on them.

Abilities

The species has unique powers. As mentioned before they can shot out beams out of their mouths, but also being able to breath in space, eat anything, eat incredibly fast, and travel through space using their beams.

Peptos XI

Peptos XI is the eleventh planet that the Gourmands have inhabited. If plan omega is executed by the queen it acts like a retreat plan, where the Gourmands eat their whole planet and use that stored energy to propel themselves to a new planet. Peptos XI was a vibrant pink color having mountains and not being to urbanized from what we can see.

Perks

The perks are mostly notable by their lighter green color and overbite. The ones inside the omnitrix also sport 4 tongues that can be used to grab things, and not being able to properly digest earth food.

Murks

The Murks are a darker swampier green also having darker green spots all around their bodies, also having an underbite. The omnitrix murk also shows only one tongue and having the ability to digest earth food.

Rumbletum

Both Perks and Murks are at odds separating themselves in battles and meetings, being slightly aggressive towards one another. The one thing that can unite the forces of both sides is their queen, currently Queen Rumbletum.

The Queen looks to be a mixture of both species, having the lighter green color of the Perks, the spots of the Murks, and not having an over or under bite. A notable feature of the Queen is her height being at least double the size of a regular Gourmand (sizes in the series is inconsistent). The queen seems to have the total authority to command her people even being able to unite the Gourmands under her rule. When she goes missing the Gourmands seem to be unable to make a decision mostly because of their arguing, but a case could be made that like bees when their queen is taken they lose connection to their hive mind (All of them share a stomach, and ben is able to sense a conflict on their planet while on earth) and not allowing the people to be a productive or alive people. The queen alone also has the power to issue plan omega.