Compared to other goblins, Gummy is rather short. His skin is dark green, which is normal among goblins. He wears what seems to be a brown rag around his waist and light-grey shorts or briefs underneath (though this could also be less detailed strips of cloth). His upper thighs are wrapped in light grey strips of cloth, and his torso is wrapped with a single strip of off-white cloth, which loosely wraps around his waist twice, then from one hip to the opposite shoulder, back to the waist, then to the other shoulder, where it is wrapped a single time around his neck, where the end of the cloth is then cast over his right shoulder. The cloth is more tattered and full of holes the higher it is on his body. His right nipple is occasionally visible. Like most other goblins, Gummy has pointed teeth, two of which are usually visible when he speaks. Which is also common among other goblins, Gummy has pointy ears which twitch if attempted to be touched.
Gummy is visibly upset by any physical contact when Finn first becomes king, due to having "not known a friendly touch in some time," which implies that Gummy was often spanked by Xergiok. His fear of physical contact quickly dissipates, however, evidenced by his admission of feeling comforted while sitting in Finn's (Whisper Dan's) lap.
He is revealed to be quite selfless; despite his obvious hatred of spankings, Gummy offered to take the place of two goblin servants when he believed Finn was about to spank them for rule breaking.
It would also seem he is very honest, as evidenced by his refusal to allow Finn to break a royal rule, despite being the only other witness. This could also be that he adheres very strictly to the royal rules, regardless of circumstance. This is further evidenced by the fact that he wouldn't allow King Finn to break any of the most trivial rules, including chewing his own food.
Finn: "Gummy, just let me do this, no one would know."
Gummy: "I would know!"
- Gummy is voiced by Michael J. Anderson, best known for playing the "Man From Another Place" on Twin Peaks and Samson on Carnivàle.
- Gummy is similar to Dobby from the Harry Potter series.
- He is female in the Latin American Dubbing.