Tate was born in 1977 to Constance and Hugo Langdon. Tate was the brother of Adelaide, Beauregard and Rose. Though he alone of the Langdon children escaped visible physical defect, he was very mentally disturbed during his time in the Murder House, in some part owning to his absentee father and neglectful mother, as well as the sadistic influence of the house itself. When Tate was six years old, Constance killed Hugo for cheating on her with their housemaid, Moira O'Hara, though Tate believed that his father ran off and abandoned their family. Constance lied to Tate about Hugo's fate, both to spare his feelings and to prevent her incarceration. Tate reached his mental breaking point in 1994, when he committed a mass shooting at Westfield High, taking the lives of 15 students.
Following the shooting, Tate returned home and was killed by a SWAT team in his bedroom. Since then, he has resided in the house as a ghost, used by the estate's malignant influence to serve as a pawn for a larger, more sinister goal.
Tate has a very grunge-like appearance, appropriate to a teenager from the early 1990s. Like his musical idol Kurt Cobain, his disposition is primarily solemn and weary. He is an attractive, fit young man with shaggy dirty-blond hair, a square jawline, intense dark brown eyes, and a charming smile.
Having been led to believe at an early age by Constance that his father walked out on him for another woman (despite the fact that she actually murdered him and fabricated this lie to explain his disappearance), Tate was forced to grow up trapped in the shadow of his mother's obsessive perfectionism and singularly treated as her favorite, oftentimes praised for being the only attractive child of her three deformed offspring. Although Constance frequently made excuses for Tate, calling him a "sensitive boy", she became verbally abusive toward him when he failed to "grace the world with his gifts", causing Tate to resent her for feeling unable to meet unrealistic expectations. This resentment toward her would only grow upon Tate's realization that Beauregard was chained in the attic like an animal, and subsequently murdered at the hands of Larry Harvey, per his mother's request, in exchange for her maintaining a sexual relationship with him. Though Tate attempted to rebel against Constance to protect his remaining siblings from tragedy, he was unable to prevent their eventual destruction and blamed his mother for damaging everyone he ever loved, causing a permanent rift in their relationship. Without a positive role model to guide him, he began to see the ghost of Nora Montgomery as his mother, though she could never remember who he was until he reminded her, from which she would only come to him begging to know the whereabouts of her lost biological child.
These circumstances, coupled with the the Devil's influence upon the Murder House - who manipulated the worst qualities of both the living and deceased within the home to commit unspeakable crimes  - began to have a profound effect on Tate's behavior, creating a dual aspect of his personality that he was unaware existed; a fact supported by his complete lack of memory regarding the Westfield High Massacre of 1994, as proven when the spirits of his former victims confronted him in 2011 looking for answers to why he ended their lives and he could not remember who they were. When he finally remembers, he becomes wracked with guilt, repeating "Why would I do that?" over and over, appalled and confused in his life's actions - traits not found in a natural-born psychopath, who lack empathy entirely. Despite this, he is fully aware that he is a ghost, though he feigns ignorance out of the fear that if it is known, he will be rejected by people he likes.
When Tate meets Violet, he bonds with her over their shared depression and the struggles they both face regarding their family dysfunction. As their relationship deepens, so does Tate's admiration for her, as she is the only person in his existence that has shown him compassion ("You are the only light I've ever known"), resulting in him falling in love with her. He starts to see that his purpose as a ghost is to be her friend and maybe something more, enforcing him to shield her from the home's malignant past occupants and stick by her as much as possible. When she accidentally dies of a pill overdose, he quickly attempts to save her life but proves unsuccessful, and mourns her death while crying "Don't you die on me Violet!". He breaks down in tears when he is eventually forced to reveal her dead body, in turn also revealing that she is a ghost, and later tries to comfort her by tearfully revealing his true feelings for her. According to Madison Montgomery, after Vivien Harmon gave birth to Michael Langdon, the Anti-Christ, all of the violent thoughts of the Murder House's residents (including Tate's) went with him, confirming that Tate's murders were due to the Devil's hold over him and that he is, in fact, the sweet-natured boy Violet knows him to be. As a result, Violet is finally able to forgive him in 2018, and the two are able to find a happy ending together in death. Sadly, these events would be reversed by the witch Mallory, who would travel back in time to reverse the Apocalypse; thus, also reversing Tate and Violet's reunion in the process.
Tate is Ben Harmon's teenage psychiatric patient. He sits with Ben at their first meeting and describes symptoms of some severe psychological issues, telling Ben about fantasies he has where he 'prepares for the noble war.' In these fantasies, Tate dons black leather clothing, a skull painted on to his face and neck, and his hair is slicked back. He kills people and has no remorse. Tate claims that he kills people he likes, and he doesn't feel anything, because he thinks he is taking them from the 'filthy goddamn horror show' that the world is to a place that is clean and kind. He asks Ben if he thinks he is crazy for these fantasies, but Ben disagrees and says Tate is merely creative and that he has heard a lot worse.
Tate has a rather strange and abrupt first meeting with Dr. Harmon's daughter, Violet. He appears in her bathroom doorway and catches her using a blade to cut her wrist over the sink. He tells her that if she is trying to kill herself, she should cut vertically instead of horizontally, because "they can't stitch that up." Violet is startled and embarrassed, asking him how he got into the bathroom. He replies that if she is trying to kill herself, she should try locking the door.
During Tate and Ben's second meeting, Ben realizes that Tate has not been taking his medication. Ben informs him that if he deems Tate a threat to society, he will have to report him to the police. However, he has not done so yet. Ben then tells Tate that everyone can get better, but that Tate has a lot of psychological issues he isn't dealing with. Ben suggests that one of those issues might be fear of rejection after Tate's father abandoned them. Tate tells Ben that he didn't take the medication because he was afraid his 'big dick' wouldn't work and that he had met someone.
Tate is sitting with Violet in her bedroom after his second session with her father. They bond over their similarities and show each other their wrists, or the cuts on their wrists, and explain what each one was for. One of Violet's cuts was because her first day at Westfield High sucked, and Tate adds that he was kicked out of that school. They realize that they have similar dysfunctional families and have the same taste in music. Tate then writes the word "TAINT" on her chalkboard, and she asks why he is seeing her father. He tells her to not ask questions that she already knows the answer to. Ben appears in Violet's doorway soon after and demands that Tate leave because it is not appropriate for him to be in Violet's bedroom. Tate then says to Ben, "What's that thing you think I'm afraid of? Fear of rejection?" and storms out of the house in a rage. Ben demands that Violet stay away from Tate.
Violet informs Tate that she is being severely bullied at school by Leah. Tate tells Violet to kill her, and that she would be doing the world a service because it would be 'one less high school bitch to worry about.' Violet does not want to kill Leah, so Tate suggests that Violet scare her instead. They devise a plan to lure Leah to Violet's house under the ruse of having cocaine to sell.
When Leah arrives, Violet takes her to the basement, where Tate is rocking in a chair with a shirt reading, "NORMAL PEOPLE SCARE ME". Leah is very confused and realizes that Violet had lied about the cocaine. Tate tells Violet to turn off the lights and the room goes dark. Tate begins to cackle as the lights flicker on and off. The monstrous Infantata pops up every few seconds, bearing black eyes, claws, and jagged teeth. Violet starts to scream with fear and the monster scratches Leah's face. Violet manages to turn the lights back on and the monster has disappeared. The two girls are alone with Tate, who is still rocking in his chair like before. Violet yells at Leah to get out and then starts to scream at Tate because she was very scared and confused. She tells Tate that she never wants to see him again, and he screams after her, "I thought you weren't afraid of anything!".
Despite this incident, Violet and Tate's relationship flourishes and they begin to fall for one another. Tate decides to take Violet on a real date on Halloween, instead of just meeting up with her in the basement of her house. They go to the beach, where they kiss until Violet moves to have sex with him. Tate pulls back and says that he does not want to yet. A group of high school students shows up, and Violet assumes that they are dressed in gore-ridden prosthetics and clothing. The students act as if they know Tate, asking him 'why he did it'. Tate acts as if he has no idea what the people are talking about. He accuses them of being rowdy high school jerks out to cause trouble and leaves with Violet.
Tate and Violet are back inside the house when they hear a knock on the door. The high school kids had followed them back to the house. Violet grabs a pair of scissors and goes outside to confront them. Tate emerges from the house and the students chase him back to the beach where they first confronted him. They continually ask him why he did 'it' - 'it' being, killing them. One girl, a cheerleader, says that she should be in her 30's by now and married with kids, but because of Tate she is dead and stuck in her current form forever. Tate still claims to not know what they are speaking of, asking why he would do something like that.
Violet decides to do some online research on Tate and discovers that he was the one who murdered the high school students who visited them on Halloween. She finds a picture of Tate, and an article speaking of how he killed 15 students at Westfield High in 1994. Violet stumbles upon a website that states that Tate was killed by the S.W.A.T. team in that very bedroom, following his mass murder. Violet makes a trip to the high school and asks the librarian that survived the shooting. Violet is desperate to know why Tate killed those children, saying that good people didn't just start shooting people. The librarian informs her that maybe Tate wasn't a good person.
Violet goes home and is overcome with sadness after the realization that Tate was a mass murderer and a ghost. She enters her bedroom and sees that he has written, "I love you" on her chalkboard. Violet begins to sob. She takes her water bottle and swallows a large number of sleeping pills in an attempt to kill herself.
Tate is dragging Violet's seemingly lifeless body across her house, screaming, "Don't you die on me, Violet!" He then laid with her in the bathtub, running the water over her head and sticking his fingers down her throat in an attempt to make her throw up the pills she had taken. She begins to cough and throw up and then starts to cry because of what has happened. Violet dies in Tate's arms and returns as a ghost, unaware of her own death. Tate hides her corpse in the crawlspace of the house so that Violet won't realize that she overdosed that day.
Tate overhears Violet's father planning to send her away, as she has been extremely depressed and not attending school as of late. Tate knows that ghosts cannot leave the premises and will eventually realize that she died when she attempts to leave. He decides that the best way for Violet to cope with being a ghost is if she makes the decision to die herself. Tate suggests that Violet should overdose on pills so she could be with him forever, "like Romeo and Juliet." Violet seems to agree at first but then runs throughout the house screaming frantically for her parents. After various attempts to leave the house, she is dismayed to realize that each time she leaves, she comes right back into the house somehow. Tate then tells a confused and hopeless Violet that he needs to show her something, and he leads her beneath the house into a crawl space, where her rotting body has been hidden. Violet becomes overcome with sadness when she finds out that she is dead, and Tate tries comforting her by saying that although she died crying, she died safe and loved.
Nora Montgomery wants a new baby because her own child had been turned into the Infantata. Tate has guaranteed that he will give her one. Although he failed with the house's former owners, Tate was able to trick Vivien Harmon into thinking he was her husband. He raped and impregnated her. Nora later asks for her baby, but Tate refuses because he is now in love with Violet. He says that he can't give Nora the baby, because the baby is Violet's brother. Nora is insistent and she informs Tate that she will still take the child for herself.
Chad tells Violet that Tate is the father of one of her younger siblings and that he had raped her mother. Violet immediately confronted Tate, asking about all of the horrible things he had done. She tells him that she thought he was like her, attracted to the darkness. She says that she has since worked out that Tate is the darkness itself. Violet says that she loves him, but that she cannot forgive him. Violet tells him to go away. Tate is overwrought and begins shouting "You're all I want! You're all I have!" in a plea for her to let him stay. However, Violet continues to tell him to go away and he disappears.
Tate is with Hayden as they watch the deceased Harmon family setting up a Christmas tree. Violet seems happy until she meets eyes with Tate, and her smile falters. Hayden tells Tate to give up, but he says that he will wait forever for Violet to forgive him if he has to.
Tate is having a session with Ben. He's trying to get Ben to talk to Violet for him when Madison and Behold walk in. Tate gets upset because they are supposed to be the ones to decide who gets to see them. Madison says that they're just here to get some information on Michael Langdon. Tate warns them that even people with magic aren't safe in this house as he walks away. He's referred to later by Constance in a recount of Micheal's origins and her eventual choosing to die in the murder house. His resentment towards her may have gone down over time; as she recalled waking to see all of her three children present, him included. He even seemed to welcome her affection as she greeted him and his brother Beau.
When Michael used to live at Murder House, Tate caught him looking through his things. Michael tells him that he just wants to be like his father. Tate refused to believe that he's Michael's father. That even he couldn't have created something so evil. Later, Vivien tried to kill Michael but Michael set her on fire. Tate saved her from the fire.
After Madison talked to Violet, Violet called out his name. He came running down the stairs to her. He begged her again for forgiveness and she finally accepted because he saved Vivien. The two of them embrace.
- To Ben Harmon: "I was afraid my dick wouldn't work.. Because I've met someone."
- To Ben Harmon: "I prepare for the noble war. I'm calm, I know the secret. I know what's coming and I know no one can stop me, including myself. I kill people I like. Some of them beg for their life. I don't feel sad. I don't feel anything. It's a filthy world we live in. It's a filthy goddamn helpless world, and honestly, I feel like I'm helping to take them away from the shit, and the piss, and the vomit that run in the streets. I'm helping to take them to somewhere clean, and kind. There's something about all that blood, man. I drown in it. The Indians believed that blood holds all the bad spirits, and once a month in ceremonies they would cut themselves to let the spirits go free. Now, there is something smart about that, very smart. I like that. You think I'm crazy?"
- To Violet Harmon: "If you're trying to kill yourself, cut vertically. They can’t stitch that up. And if you're trying to kill yourself, you might also try locking the door."
- To Violet Harmon: "Something has changed in you. Towards me. You're distant, cold. I don't know what I've done, but I'll leave you alone from now on if that's what you want. Is that what you want? You know why I'd leave you alone? Because I care about your feelings more than mine. I love you. There, I said it, not just on some chalkboard. I would never let anybody or anything hurt you. I've never felt that way about anyone."
- To Violet Harmon: "If you love someone, you should never hurt them."
- To Violet Harmon: "Hi I'm Tate, I'm dead, wanna hook up?"
- Tate Langdon is the first character portrayed by Evan Peters. For a complete list of his characters, see Cast.
- Interestingly, Tate's eyes become an oily, ink-colored black while donning the Rubber Man suit, as displayed when he raped Vivien Harmon. This may imply that there is more to Tate than we have seen.
- Main article: Tate Langdon/Media
- ↑ Episode: Smoldering Children
- ↑ Episode: Return to Murder House
- ↑ Episode: Halloween: Part 2
- ↑ Episode: Afterbirth
- ↑ Episode: Birth
- ↑ Episode: Piggy Piggy