Indigo is ultimately antagonistic towards every Crewmate they see because they believe they are all a danger to the lives of the Impostors that they intend to protect despite being a former Crewmate, and would not hesitate to kill them if necessary. Their main goal is to protect their fellow Impostors that hides in the Impostor Hideout, which is a location that they are the leader of. They have shown huge hatred towards the Mira HQ Scientists, especially Dr. White, for experimenting on the Impostors, as well as disliking the Rescue Team since they work with the Mira HQ Scientists. But they are grateful to those who manages to do something successfully that benefits them, such as when Indigo gives Green a thumbs up when they manage to vote out all the other Crewmates. While Indigo has good intentions of shielding their fellow Impostors from what they perceive as a threat (like the Crewmates), they are very dangerously easy to anger. Their anger issues often clouds their judgment and causes them to be proned to impulsive and reckless behavior, sometimes killing other Impostors either intentionally or unintentionally. They also believe they know what is best for all of them and is not afraid to speak up their mind, but would not mind letting the others pick and decide if they think it is necessary. After coming back from their expedition above, they have given Dark Slate Blue meat despite the fact that they are now old and lack any teeth at all, which could indicate that Indigo is rather insensitive to their own parent's condition. But regardless, they have shown to at least have some degree of respect for the elder Impostor since they followed Dark Slate Blue's commands at one point.

Unlike most of the other Impostors and Crewmates seen, Black doesn't speak. However, it's obvious that they are very bloodthirsty and sadistic, as many body parts of both Boyfriend and Crewmates are seen in their song Defeat. Black is also very determined, as they chase Boyfriend and Girlfriend across the Airship in an attempt to kill them. That said, their patience is not without its limits, as they scream in frustration after the duo evade their wrath after a certain amount of time. Black is also very intelligent and strategic, being able to ambush and kill an entire room of crewmates (Boyfriend and Girlfriend included) by sabotaging the lights immediately after jumping out of the vents, albeit with some help. They also incredibly manipulative, as demonstrated when they convince everyone to vote Gray's father to be executed. By further extension, Black raises Gray, a crewmate to become a murderer like them, turning the child insane as he grew older. While they work with other Impostors and murderers, such as White, or their adoptive child, Gray, nothing states or implies Black cares for any one other than themselves. An example of this is shown in an unused cutscene where White and Black find Red's body shortly after he was voted as the Impostor. While White was disturbed by this turn of events, Black simply nudges them with their fist, showing how little they care for the other Impostors.

Like most other characters in the series, Mono rarely speaks. Instead, his personality is shown in his actions, and it was stated in an interview that Mono is protective, particularly towards Six (Or your oc). Mono appears to be a confident, well-meaning boy who is willing to go out of his way to help others, as shown when he persists in freeing Six from her apparent imprisonment in the Hunter's cabin and offers his hand to her. He stays by her side, offering his help again when she asks for it despite her initial rejection of his assistance. He has a degree of compassion, being very clearly disturbed by the decaying bodies in the Hunter's house, as well as initially being shocked upon seeing Six in her monster form when he finds her in the Signal Tower.

Brown is incredibly determined to find out who the imposter is, to the point where he seemingly forces other crewmates into interrogations and wrathfully yells at them not to lie to him about being innocent. Ultimately at the end of the day, he has the best intentions of his fellow crewmates at heart and only wants to stop the imposter from butchering anymore innocents.

Brown is more skeptical and less easily persuaded than their co-workers, as they did not believe in "Olive"'s lies, and when the votes were changed, Brown threatened the latter with death if Yellow turned out to be innocent. However, when Yellow is proven to be an "Impostor." Brown goes back on it, now trusting "Olive" to be a Crewmate. When Brown sees "Olive" over Orange's body, this trust disappears as they regret voted out Yellow, and Brown makes a run for it after losing their report megaphone. It should be known that it is not the only Impostor activity that Brown is stern to. Any sort of physical violence is not tolerated, and is even punishable by death (which is being thrown into the lava pit). Despite threatening Red with this punishment, Brown deep down was actually concerned for Red's wellbeing, even asking if they were alright. (I have to much Browns but idc >:D)

Little is known about Dr. Harlow's personality. As revealed in his hospital lobby dialogue, he has worked with the Animal Hospital for a long time and has seen many hires come and go. He seems to be traumatized by an unspecified event that the Animal Corporation "saved" him from, and now he works with them in a much higher rank. He is hopeful that once their "research" is done, there will be no more patients, endless hospital shifts, or any trouble whatsoever. Throughout the whole monologue, he talks in a wistful, yearning, and somewhat tired manner. The only things Dr. Harlow can be seen doing are sitting in the lobby while watching the player(s) do all the work, speaking with an Animal Corporation employee in a hazmat suit outside the hospital, going to the staff room, or coming to the reception office after the shift has ended. Dr. Harlow is presumably a bit of a coward. During the first emergency, he doesn't do anything to help the player(s) take care of the large amount of incoming patients—instead, he immediately runs into the staff room.

White is a wealthy and privileged person who believes their success comes entirely from their own hard work, despite having received many advantages throughout their life. Because of this, they often fail to understand the difficulties faced by others and assume everyone has similar opportunities. White is somewhat self-centered and unaware of their privilege, which can make them seem condescending. When problems arise, they tend to wait for others to solve them rather than taking action themself

Combat Skills: The Chosen One is shown to have excellent hand-to-hand combat skills when fighting against the Animator, programs, and other stick figures. Weapon Proficiency: The Chosen One is shown to wield weapons and other objects proficiently in battle. Natural Adaptability: The Chosen One can naturally adapt to the environment or situation he’s in, especially while he’s trying to figure out ways to fight back from victim in The Box. In combat, The Chosen One has displayed ingenuity and flexibility, as well as extreme adaptability. In The Box - Animator vs. Animation 10, he repeatedly altered his strategy against the Box's power-nullifying. He tends to rely on his pyrokinesis and laser vision during battle, but can resort to other options when needed. This neglect of his other powers overall leaves him generally weaker and less flexible in battles which may need it, such as his battle against The Dark Lord, however this does mean he is extremely versed in those specific powers, demonstrating a mastery of their utilisation. He fights somewhat recklessly, due to his ability to adapt and nullify different special effects and his high durability.

Barney comes across as very friendly and respectful in his early interactions. Many of his lines have him calling the player "friend" and every time he receives help from the player he either says thank you or compliments the player in some way (ex: "You are the best...") mostly for giving coffee. Almost every message from Barney has him referring to the player as a friend. Despite this, he uses the player as much as possible, and comes off as very demanding and manipulative rather than kind, as he gets upset if the player refuses to give him what he asks for. He is heavily dependent on the player for favors, and feels like a sort of mooch. Once Officer Duckman arrives at the hospital, his appearance changes. If the player speaks to him, he tells the player that “friends do not turn each other to the police…” and even says “If you speak, I will kill you, friend…” hinting that his previous kindness could've been fake and showing his true motives. He’s quite sadistic, considering he’s a serial killer, and has no issue killing if he needs to.

From the moment they were introduced, Blue was described as the "hot doctor" of the crew, being very popular because of their physical appearance and career, as well as the most capable member, even outclassing Purple, who is a more serious and focused Crewmate, and Red, despite Red being the captain and technically having higher authority. Blue came off as charismatic, determined, and poetic, having a doctorate in poetry, and caused almost the entire crew to "swoon" over them by simply speaking inspirationally and looking at another Crewmate, including Purple who is usually the more grounded member of the crew. This is shown in "You Can't Be Hot and Smart" where they make almost every Crewmate in the episode fall in love with them. Blue had a very keen intellect, as they came up with the idea of using Orange's backup trust balls to seal a hole in Storage caused by an asteroid. They also knew their crew very well, as shown when they were able to lure Lime (who is usually paranoid and disconnected from the crew) out of the vents and convince them to scan. Blue cared for their crew's safety, being determined to ensure everyone's safety following White's death.

Brown was first shown to be a rather introverted and a lone-wolf character typically avoiding the crowd otherwise backing up their co-worker and fellow union-loving best friend: Yellow. Brown was a very calm character yet one who prioritizes justice and righteousness over any sort of prematurely established "status quo" as displayed when they demanded Red to change the elimination system, when Red affirmed that their method is simply the way it works. Unlike most of the delegates during Yellow's trial, Brown abstained from it, successfully representing their premium on their denial to indulge with or engage in a harmful environment - or trial for that matter - even by means of superficial pressure and conformity. Brown was quite in touch with their mind and their core values as portrayed not only by their refusal to participate in votes but also when they quietly accept their demise upon the Impostor's arrival within the kitchen. They were very morally conscious as well as sentimental.

The "Intern" Mask: While blending in, Green acts as a naive, eager, and hardworking crewmate with a "can-do" attitude. Their official task is simply "whatever they're told". The True Mastermind: Once their disguise drops, Green is a cruel, calculating, and greedy Impostor who cares little for others. They methodically use manipulation, frame others (like planting evidence in Yellow's backpack), and exploit ventilation shafts to pick off the crew one by one

Red, at the beginning of Season 1, puts on a mask of bravado and confidence, even after the first Crewmate dies. Beneath the surface, however, they are unsure and panicking because of the carnage happening around them and their inability to contain it. They are insecure, often claiming credit for the good ideas of others, and use this as an attempt to maintain some form of authority over the crew, albeit unsuccessfully. Towards the end of Season 1, Red begins to become more aggressive as the instability of their inner mind increases. They become concentrated on self-preservation of their reputation and being correct; despite that, when they realize their faults and ultimately reconsider the situation, they step up to vote against Green, claiming that they were wrong in what they did to Purple. They care for their crocs too, and this is proven by them freaking out when they soak them in White's blood in You Can't Be Hot And Smart.