Gwog

Gwog is an alien who abducted Thaddeus Euphemism twice.

Appearance
Gwog has green skin, four arms, and one eye that's on a stalk, but other than that, his appearance seems to vary.

Initially, he was about as tall as Bob and had a slug-like body, but later, he was about as tall as IBall and had short legs. At one point, he had a crop circle tattoo on his posterior. His outfits (when he's wearing any) vary.

Personality
Gwog seems to be impolite, but not really evil. He abducted Thaddeus, stripped him, and wanted to probe him but never expressed any desire to actually harm him.

He also judged the nerds at Comic-Con for being unusual despite all humans being an alien species to him and kept Thaddeus awake one night.

This impolite behaviour seems to be an attribute specific to him rather than a species trait, as other members of his species have called him a "jerk" for it.

Trivia

 * His species don't have a nudity taboo, although many wear clothes anyway.
 * He's referred to as an "intergalactic alien" by Thaddeus. If that's correct, he is not indigenous to the Milky Way.