Gregg is talkative, exuberant, and rebellious. He is a very punk-like character. But despite his loud and optimistic demeanor, Gregg has a fear that he may accidentally ruin his relationship with Angus.. He is also known to be very excitable, frequently expressing said excitement by shouting or flapping his arms rapidly. However, he has also been seen to have poor impulse control.

Though he's a troublemaker, he cares about his friends and is willing to help them out when they need it. He frequently asks how they're doing, and isn't afraid to express the fact that he cares about them. He has serious moments as well, and has messaged Mae on occasion telling her that he's having a rough day.