Mr. Gus is a tall, green, scaly dinosaur man. He wears a white tank top, and no pants. He has a pink mouth, and a gap.
Mr. Gus is very nonchalant and laid back. He has a deep voice, and it's always monotonous. His expression never changes whether he is happy or surprised. He usually always has the same expression except for on occasions when he screams or his eyes go wide. Mr. Gus seems to be smarter then the rest of the crew, and the most level headed, though he is sometimes ignored like in the episode Funny Face when he told UG and Pizza Steve that they shouldn't make funny faces because they "cause a lot of pain".
Mr. Gus is also very helpful and nice despite his appearance. He doesn't mind helping others, and he cares about others.
It is shown on numerous occasions that Mr. Gus sees through Pizza Steve's bragging and doesn't believe in it. He is usually who Pizza Steve throws the blame for him not being able to do what he claims he can, but Mr. Gus doesn't respond to this.
Uncle Grandpa - Uncle Grandpa is always doing ridiculous things and Mr. Gus is always correcting him and trying to make him stop, but he never listens to him. Mr. Gus is always a stick in the mud when it comes to this sort of thing. He will constantly try to tell Uncle Grandpa the same thing throughout all of his crazy adventures, but he will always ignore him. Although Mr. Gus is constantly annoyed by Uncle Grandpa, he still likes him and they are good friends.
Pizza Steve - Pizza Steve and Mr. Gus are sort of like frenemies. Mr. Gus is annoyed with Pizza Steve because he is always lying about himself. Pizza Steve is always getting things wrong and Mr. Gus is always correcting him, but Pizza Steve never listens. Mr. Gus and Pizza Steve have sort of a rivalry going on with each other where they'll constantly argue with each other. It will mostly be about how Pizza Steve is lying about something or about how Mr. Gus isn't any fun. but when even though they fight a lot, they are still best friends and they like each other more than they hate each other.
Giant Realistic Flying Tiger - Mr. Gus seems quite fond of Giant Realistic Flying Tiger. She seems to return this affection namely by giving him tiny "kitty licks" on his face and saving him, Belly Bag, Uncle Grandpa, and Pizza Steve from the zombie pets.
Other Dinosaurs- Mr. Gus is seen with two other dinosaurs that are his friends or family members. The trio make their debut in More Uncle Grandpa Shorts.