Injured when Tex threw a plasma grenade at his helmet, Donut is consequently airlifted out of the gulch for medical treatment. Pleased that he captured the Blues' flag, Red Command gives him his own armor color, which becomes a sensitive issue for him: he insists that his new armor is "lightish red", even though it is clearly pink to everyone else. As the series progresses, the armor color and the trauma he received from Tex seem to take their toll on Donut's mind; his speech and personality become increasingly effeminate. He also becomes more childish, pretending to be a secret agent during a reconnaissance operation, and later sticking his hand in machinery despite repeated warnings against it.
A reason he may act like he does is because the right side of his brain was damaged brutally by the grenade, causing him to lose most of his logical and social functions. However, it is possible that Donut was always like this, considering that he received the plasma grenade injury in the same episode he debuted in. In episode 74, it was said that he often enjoyed putting on a cop uniform and short-shorts, referring to himself as "Officer Hotpants." He had done this before when the Reds had attempted to celebrate Sarge's birthday, with Donut hiding in the cake in this outfit.
Despite these flaws, Donut sometimes demonstrates alertness or knowledge beyond that of his teammates. For example, in season 2, he is the only one to suggest correctly (at the time) that Church is a ghost (and hence why Sarge went mad, and Lopez ran away). Left to his own devices when the other Reds leave him behind in search of a distress signal, he is left being chased slowly by Lopez's robots. Donut manages to steal O'Malley's Ghost (or as he calls it, "motorcycle") and catch up to his team. Nevertheless, his insights are ignored by his team.
Although he is evidently a beneficiary of "Don't ask, don't tell," it's rather difficult to hit his sexual orientation. While it is commonly believed that Donut is gay, it is revealed in one of the alternate endings, Where Are They Now? that he is in fact a heterosexual. He marries an exotic dancer named Tiffany and they have 12 kids. However, when asked by Sarge what the word was for choosing between two things you'd rather not do, he eventually suggested "a threesome with cheerleaders."
Donut is now apparently dead after a brutal attack on Val Halla. It is implied that Donut was shot in the head with a pistol by the former freelancer, Agent Washinton. It was revealed in the first episode of Revelation that he is indeed dead.
Most characters in the series have positive feelings toward Donut, even Church, who is from the Blue team, although most members of the red team are uneasy around him, as he often says or does things that contribute to his metrosexual personality.
During season 9, Donut's personality had some changes due to Epsilon's memory being corrupted. In Epsilon's memory, Donut is actually "a repressed meat-head" that acts like a jock, though does say things that are ambiguous if taken out of context. For instane, when Donut told Simmons to fire another rocket at them, he said "We'll shove this one right up their ass." Another example is, when he told Sarge to send cover fire at the Blue team, he said he and Simmons would "Take them from behind and slip right on in." It is because of these quotes and sentences that Donut makes Simmons uncomfortable. Donut secretly kept a diary from everyone else, calling it a log-book, which Simmons had no knowledge of and Grif said "I won't ask, he won't tell." However, after having a long talk with Sarge about emotions, he seems to have gone back to normal.