- "Mister Caboose, I just want you to know that even though we are on different teams, and we may never see each other again, whatever happens out there today, I'll always remember the moments we shared together. You are now, and forever will be... my friend."
- —Donut to Caboose
- "...Private Donut? That sounds like Private Biscuit."
- "Yes. It, does."
- —Donut in K.I.T. B.F.F.
Although Donut tends to annoy all of the Red Team members, some of them seem to take a liking to him.
Sarge seems to like Donut, never directly insulting him and respecting him as a teammate. However, he is sometimes disturbed by his strange sayings and actions like other characters. Sarge also considers Donut to be the Grenadier of the Red Team and it shows how useful he can sometimes be. However, after Sarge fell into the caves in Season 5, he believes he was sent to Hell upon seeing Donut down there with him.
Excluding the time Donut was practically ditched in Episode 57 (though that was partially due to his loss in the "not-it" policy), Sarge refuses to leave Donut behind, further signifying his care for and respect towards Donut as a teammate. Sarge has also admitted to "[being unable to] stand Donut being captured another minute" in the Blue Base in Chapter 5 of Recreation and even claimed to miss Donut after his "death" in Chapter 4 of Revelation.
Grif regards Donut with disdain, thinking him unintelligent, and evidently despises the rookie's general enthusiasm. He also admits to being uncomfortable when others express their feelings towards Donut, such as after he was crushed by Sister's ship in Season 5. In Relocated, Grif was the one who found Donut before the latter went into a coma. When Caboose suggested that Donut kill Grif in order for Sarge to allow Caboose to use the Hologram Chamber in Local Host, Donut wasn't against the idea, but didn't go through with it because the Reds have rules regarding team kills. When Donut returned in Season 11 and acted enthusiastic about being "A group of strapping young men out in the wilderness," Grif responds with "I'm starting to remember why I don't like you."
Donut tends to annoy Simmons at times (such as during their "Shotgun!" calls on the Warthog, or when Donut constantly accuses Simmons of doing drugs in Season 5), but they usually get along quite well as a team. Simmons continually gets annoyed whenever Donut makes any remark on what was going on (maybe due to the fact they sounded sexual) and briefly hated Donut for taking his job in Season 4. However, after Donut is crushed by Sister's ship in Season 5, Simmons shows that he cares for Donut, saying that he would "miss him like a sister." He additionally even attempts to save Donut after he is shot in Think You Know Someone. Likewise in Season 11 Simmons is momentarily horrified along with Washington when Donut is incapacitated by a grenade explosion which lead him to believe that Donut had been killed.
When Donut is discovered to be alive in Three's a Crowd, Simmons seemed quite happy. However, Simmons also became angry to the point of attacking Donut with the rest of the Reds and Blues in Long Live the King.
At the beginning of the show, Lopez hates Donut, even going so far as to saying he could kill him - very much likely due to Donut providing incorrect translations for what he is saying most of the time and pestering him with nonsensical questions in Episode 75. Due to a number of circumstances, Donut and Lopez are often found in each other's company, much to Donut's pleasure and Lopez' irritation. In Recreation, Lopez even suggests to Simmons numerous times that they kill Donut and bury him where no one would find him. However Donut never seems to take note of Lopez's disdain towards him. Donut respects Lopez and refuses to leave him behind, as Lopez has (according to Donut) been loyal to the Red Team, as stated in Retention Deficit.
As the series progresses, Lopez begins to shift from utterly despising Donut to tolerating him and even coming to terms with Donut's childlike demeanor. On his end of things, Lopez, while clearly frustrated at Donut's inability to translate, still saved him in Season 12 by incapacitating Donut's would be killer with a punch to the head, insinuating that he doesn't really hate him badly enough to let him die. Lopez also seems to consistently work with Donut in the later episodes more than anyone else on the Blood Gulch Crew, even to the point that Donut becomes his co-pilot, showing that he prefers Donut's "brand" of character compared to everyone else. Hinting at that Lopez has become used too and even comfortable interacting with Donut.
Everyone on the Blue Team seems to like Donut, believing him to be harmless, except for Tex, whom he had "killed".
Although Church does not have many direct interactions with Donut, Church actually likes him. He admits to Simmons in Episode 70: "I like Donut; he's pretty harmless man. I don't think he'd hurt a fly," even though he killed Tex in the first season. He additionally defends Donut's armor color, calling it not pink but "slightly less red."
In Got Your Back, when Church discovers that the ship crash-landed on Donut, he says in response, "Oh, wait, the pink guy? Oh, I actually liked him!" As a side note, when Church took over Donut's body in Episode 37, he admitted to liking Donut's armor, calling it comfortable and roomy.
Caboose and Donut, although being on different teams, are great friends, which Donut acknowledges in Episode 38 after being captured by the Blues. (Though, when Donut was released back to the Red Team, Caboose bids him farewell then questions Tucker, "Who was that guy?" possibly showing that he either forgot about the bond the two made in the previous episode or that he was on the other team). In Dealer Incentive, while Donut was held captive at Blue Base, they were shown playing playing Truth or Dare, continuing to build their friendship with one another.
As a running gag between the two characters, Caboose often confuses Donut's name with other types of pastry, calling him "Private Biscuit", "Lieutenant McMuffin", "Admiral Buttercrust", "Commander Poppin Fresh" and "Major Cinnamon Bun", in their first encounter at Blood Gulch. This is also referenced at the start of Recreation, where Caboose recognizes Donut as "Muffin Man" (although from then on Caboose manages to get Donut's name right).
Donut does not seem to notice how unintelligent Caboose is, unlike the others. Donut even views him as responsible, in a sense. In Well Hello for example, Donut believes that Caboose would make a great dad due to his efforts in building a new person. Caboose's mental image of Donut is a girl who has a crush on Caboose and believes her sniper rifle to be a purse. Despite their friendship, in Season 4, when Sarge was observing Caboose and Andy through a sniper rifle Donut suggested shooting Caboose in order to retrieve Andy. It's worth noting however that Donut did so not out of any malicious intent or hatred towards Caboose, but simply out of respect for Sarge.
Donut and Tucker haven't had much interaction with one another. When Donut is captured in Season 2, Tucker believed him to be a girl, due to his pink armor. Tucker also believed that his name was dumb, after Tex tells him about Wyoming. Donut seemed interested in Tucker's sword when he first obtained it. After Tucker tells him that he got it inside a hole, Donut replies saying that he looked inside every hole he could think of, which disgusts Tucker. In Recreation, Donut finds a distress beacon from Tucker, and informs Caboose, as well as his own teammates, about it.
Tex and Donut have little interaction, their main ones being her sticking him with a plasma grenade and him "killing" her in Episode 19 (additionally calling her a dirty whore) because she's responsible for his pink armor. When Tex came back in Season 2, she refers to Donut as "the bitch who killed me," however she does not attack him. When Donut was stuck with Tucker, Tex, and Sheila in Episode 39, he complained to Tucker about Tex (and Sheila) boring him, as the two talked about "chick stuff, and not the fun chick stuff like ribbons and unicorns."
When the other Reds, Church and Caboose left Blood Gulch to chase Omega/Doc, Donut was left alone with Sheila, who thought he was being perverted when he stared at her treads. Later on, when Tex appeared, he was bored because the two talked about 'chick stuff.' However, before Tex, Tucker, and himself went to join the others on Sidewinder, he appreciated her generosity for giving them lunch bags.
While the two never interact Donut was crushed by Sister's ship when she first arrived at Blood Gulch.
Donut doesn't know Washington very well, only physically (and knowingly) meeting him once. When the two meet in Chapter 19 of Recreation Donut believes him to be a friend of Simmons and believes he will save them from The Meta. However, Wash demands the Epsilon Unit, but when they don't answer, Wash shoots Lopez and Donut in an effort to get Simmons to talk, and Donut goes into Recovery Mode.
Following the rescue of Epsilon from the UNSC archives and his reunion with his squad, Donut refers to Wash as a jerk for having shot him in the stomach and staining his armor with blood. When the squads returned to Valhalla, Donut seemed unaware that Washington was on the Blue team or who he even was, at one point asking Simmons "Who is the blue guy with the yellow accents? His voice sounds familiar." In True Colors, Washington redeems himself by saving Donut from a Tex drone.
While the two were rarely shown interacting with each other, Donut was perfectly willing to risk his life to save Freckles from being destroyed by Lopez 2.0 in Fire. Later on, during The Federal Army of Chorus, Donut was horrified upon learning that Freckles had been destroyed by Locus.
Despite fighting each other, they did not interact much with one another. It is worth noting however that when Donut first saw O'Malley, he referred to the latter as the "cave devil." Additionally, when Donut was left behind in The Storm, he manages to steal O'Malley's hovercraft, run over a member of his (and Lopez's) Robot Army, and catch up with the rest of the Red Team. When Omega possessed him, Donut became more feminine and defensive about his body.
During the battle at Crash Site Bravo, Donut interacts with Lopez 2.0 greatly, as he tries to convince Cyclops/Lopez 2.0 to stop his actions, reluctant to kill him despite his betrayal. However, after Lopez 2.0 insults him and calls him "pinky," Donut reveals he also understands Spanish, correcting him that he's lightish red, shocking the robot. Donut then kills Cyclops/Lopez 2.0 by using the "future cubes" and Simmons' minefield.
Initially believing them to be the enemy, Donut has grown to like many of the soldiers of the Federal Army of Chorus.
Donut is shown to greatly like Dr. Grey and usually describes her as 'nice', mainly due to the contributions she provides for the Blood Gulch Crew. Donut has also stated because Grey is a doctor, she's "like a medic who saves people." However, at times, he is somewhat afriad of her methods. During Season 13, Donut has seemed to liken up to Grey and joins her in chasing down Doc during The Thin Fed Line.
During their first encounter, Doyle faints after Wash threatens him, resulting in Donut calling him "a weenie." After Doyle explains the Federal Army's situation to Donut, Sarge, and Wash in The Federal Army of Chorus, Donut begins to trust Doyle and agrees to help him and his army defeat the New Republic. However, after learning of the Space pirates' manipulation of the two armies, Donut and the Blood Gulch Crew go to great lengths to save them.
After learning of the Space Pirates' involvment in the Chorus Civil War, Donut greatly dislikes Charon Indutries and its members.
Ever since his first encounter with Locus, Donut has never trusted the mercenary, due to his dark presence and unsettling nature. During the Battle of Crash Site Bravo, Locus incapicated Donut first before taking him captive. In The Federal Army of Chorus, Donut is horrified after Locus tells him and the others of Freckles' destruction. Donut has also stated "[Locus] doesn't make any sense," because of his actions and statements.
Donut initially trusted Felix after the latter defended him and the other Reds and Blues during Season 11, and was joyful when Felix described them to be the galaxy's greatest soldiers. However, Donut's view of Felix completely went south after learning that he and Locus were working together to eradicate Chorus' two armies and used the Blood Gulch Crew to achieve this. As a result, Donut has lost all respect for Felix.
Donut is partially responsible for Doc ending up in Blood Gulch as he is the one who injured Tex, which led the Blues to call for a medic. Originally, when he saw Doc talking with Omega about their plans, Donut showed great fear of him and called him the "cave devil". However, later on in the series, Donut developed a friendlier relationship with Doc, such as when after Doc saved his life from a gunshot wound, the two began living together in Valhalla during Season 10. When he discovers the Reds and Blues are stranded in Season 11, Donut brings Doc with him to "rescue" them. It's also implied the two are now best friends, as Donut's Basebook page has an image of him and Doc with the hashtag BFFLS, which is plural for "Best Friends For Life", in Reconciliation.
In spite of that however, Donut, along with everyone else, seemed completely oblivious to the fact Doc was missing for two and a half seasons, stating that it felt like he "hadn't seen him in ages".
Although the two are never shown to interact with one another, Donut somehow knew that Vic had a vasectomy, which couldn't have allowed him to have had children in the future.
In Well Hello, Donut comically tries to start a conversation with the Meta, oblivious to the fact that the Meta was trying to kill him and believing he was simply cleaning. When the Meta does not reply to Donut's welcome, Donut merely shrugs him off as a "strong silent type" and continues to assume him to be a new Blue recruit. He even regards the Meta's unintelligible responses as to what his name was as "foreign," additionally loving his "accent." However, after learning from Simmons and Lopez who the Meta is, he aids them in fighting against him.