Theodore Peterson

Theodore Peterson, commonly known as Mr. Peterson or The Neighbor,' is the Main Antagonist of Hello Neighbor. He always tries to keep the player from breaking into and entering his home.

Past
Mr. Peterson was once an am Peterson, he once let a younger Nicky see and befriend his son, however, due to a horrible car accident, his wife had to be hospitalized, Mr. Peterson became anxious, waiting in the hospital until his wife eventually died in there, not long after Aaron accidentally pushed Mya off the roof of his house, leading to her demise too, with the death of his beloved wife and daughter in just a short amount of time, these two incidents severely crippled Mr. Peterson's sanity.

Hello Neighbor: Hide and Seek
Mr. Peterson plays a minor role in this game as the game focuses more on his two children, Mya Peterson and Aaron Peterson, Mr. Peterson is seen at the dinner table along with his wife and two children, Mr. Peterson is seen again entering the house with his wives purse, he then lets it go before collapsing to his knees, Mya and Aaron hug their father to comfort him, however, this wasn’t enough as Mr. Peterson became more sluggish, watching TV and appearing not to notice his daughters concerned look for him even though she was right in front of him, he appears again to get the children for dinner, motioning his hand tiredly, at dinner Aaron takes Mya's spoon before pushing her and causing her plate to fall and break, seeing this, Mr. Peterson gets up and sends Aaron to his room, but before he leaves he takes Mya's doll, Mya goes to get it back but Mr. Peterson motions his hand to tell her to stay and eat dinner. Aaron later plays hide and seek with Mya’s Doll, but accidentally shoved her off the ledge out of anger that she won. Mr. Peterson is seen one final time during the credits, digging a grave, probably for Mya.

Act 1
Nicky watches as Mr. Peterson locks Aaron in his basement, possibly to either punish him for Mya's death or to protect him from meeting his wife and daughters fate, Mr. Peterson then finds out that Nicky is watching him and throws him onto the other side of the road as he goes to lock the basement door and hide the basement key, Nicky has to outsmart and evade Mr. Peterson as he eventually finds the key to the basement, Nicky finds a corridor in Mr. Peterson's basement, however, Mr. Peterson is behind him, Nicky tries to escape but the door at the end of the corridor was locked with 3 padlocks, allowing Mr. Peterson to catch Nicky and end the Act.

Secret Neighbor
In Hello Neighbor: Secret Neighbor, Mr. Peterson has successfully captured Nicky and has locked him in his basement, so 5 unnamed kids decide to rescue him, like Nicky, the 5 children must outsmart and evade Mr. Peterson to help Nicky escape as Mr. Peterson doesn't intend to let him go and now wishes to imprison the 5 children who dared to invade his property, Mr. Peterson will disguise as a child to pick off the children one by one unless the kids manage to find out which one of them is Mr. Peterson. The game takes place between acts 1 and 2 of the main game.

Hello Guest
In the novel, Hello Neighbor: Bad Blood by Carly Anne West, the story of the Forest Protector or The Neighbor was shown. They are creatures with human bodies and crow's beaks. According to the story, they protected the forest and eventually developed a taste for human blood. The Forest Protector is the main antagonist of Hello Guest, giving the Night Watchman / Ike Gershowitz heart attacks and trying to prevent him from exposing the weather station hidden behind a wall. In the Bad Ending, he destroys the wall and building with mines by blowing them up.

Act 2
The opening cutscene reveals that Mr. Peterson has kidnapped Nicky and has been possibly torturing him, Aaron Peterson is shown to save Nicky from the room in the basement he's locked in (looking through keyhole shows this). Once Nicky escapes his prison he has to once again outsmart and evade Mr. Peterson to escape the horrid basement, once Nicky finally escapes, One can hear a couple of windows break hinting Aaron is attempting escape as well, Mr. Peterson doesn't chase him but instead chooses to go and re-capture his son. Mr. Peterson then closes the wooden gate while threateningly staring at Nicky, the Act ends when Mr. Peterson completely shuts the gate.

Act 3
In this Act it is revealed that Nicky still has nightmares about Mr. Peterson after that day, Nicky has another nightmare about Mr. Peterson after moving into his new house, which actually used to be Mr. Peterson's house, in the nightmare Mr. Peterson has locked up Aaron like in act 1, and has locked them in his basement in his amusement park-like house, Nicky once more has to outsmart and evade Mr. Peterson to unlock the basement door, however before he can enter, Nicky must overcome his three fears from his childhood or the door at the end of the corridor will still be locked, once Nicky has overcome his fears, he is about to enter the same corridor where he was caught by Mr. Peterson, however Mr. Peterson catches Nicky, however Nicky using his new powers from overcoming his fears pushes off Mr. Peterson, enters the corridor and locks the door, if Nicky has overcome all his fears than the door at the end of the corridor will be unlocked, once Nicky enters he will be in a one-room house with a cardboard cut-out of Aaron, however a giant Mr. Peterson appears out of nowhere and destroys the house, Nicky must then climb and use the umbrellas to get on the house on the giant Mr. Peterson's back, once Nicky enters the house door he must overcome his final fear, once Nicky overcomes his final fear he will be transported into another white void with an Exit Door and a house, if Nicky peers into the house than he can see the real Mr. Peterson locking himself in a room, on the other side of the barricaded door was the Shadow Man, unlike Nicky, Mr. Peterson cannot seem to overcome his guilt and thus cannot overcome and defeat the Shadow Man like Nicky did, unable to help Mr. Peterson, Nicky leaves through the Exit Door, Mr. Peterson's fate is unknown, but he is believed to be alive.