Antisepticeye first appeared on the jacksepticeye channel on October 10th, 2016, in the video titled "THE START OF THE NIGHTMARE | Five Nights At Freddy's: Sister Location #1" which had previously been titled "SOMETHING DOESN'T FEEL RIGHT." Anti appears in this video in brief clips and there are messages—and some links in the description—that have an ominous meaning. Sometimes the message on the whiteboard in the background will change its message to something that vaguely references Anti.

Anti's next appearance on the channel is in the video "SAY GOODBYE" (written in Zalgo font) which was released on Halloween 2016. In this video, Anti actually takes over Sean's body and addresses the viewers. The video appears to just be Sean carving a pumpkin, much like he did for Halloween the year prior, but while Sean carves the pumpkin Anti foreshadows his arrival. In the video, Anti: laughs and distorts the camera; stomps in the background; briefly appears in the camera when it distorts; causes Sean's nose to bleed; and changes the message on the whiteboard in the background. Of course, he also possesses Sean's body and slits his throat while saying the viewers are to blame because they just watched it happen, and says they could've stopped him. Sean can be heard muttering "help me" but it's too late. Anti says that Sean is "gone forever" and tells the audience to say their goodbyes. The video ends by Anti jump-scaring the viewers and then it cuts to black.

In Sean's 2017 PAX East video, "ALWAYS WATCHING," again in the Zalgo font, Anti once again appears. In the video, Sean appears on a screen, and after telling the audience they'd be recording a message for an interaction game, Anti appears on the screen after making it glitch. Anti tells they audience they only thought he was gone because they'd stopped paying attention, and they replaced him with Sean. Then the virus/demon says they'll never be rid of him, he's not going anywhere. The screen goes black, and Anti can be heard saying, "Enjoy the show."

The next time anyone sees Anti is in the video "DARKIPLIER vs ANTISEPTICEYE," however it's been stated that this video isn't canon in the characters' lore, and thus cannot be counted as a legitimate part of Anti's history.

In Sean's Bio Inc. Redemption video, "KILL JACKSEPTICEYE," uploaded on August 3rd, 2017, we see Anti possess one of Sean's other alter egos and how Anti sees the channel. Sean explains that the developers of the game made and Easter egg of him, but shortly after Sean starts feeling sick and he leaves the frame. Thus, Dr Schneeplestein, one of the egos, takes his place and promises to save Sean in the game. Halfway through the video, Dr. Schneeplestein says he feels discomfort, and makes a reference to Anti when he mentions antidepressants. The virus/demon himself glitches into the video, and soon takes over the doctor's body. Only when in-game Sean dies does Anti appear, and then address the viewers. Anti says he's sick of repeating the same cycle with them, saying, "How many times must we go through this? Again and again! Fooling around. Over and over! Fucking circles!" Then he berates the fans for giving him the nickname "glitch bitch" and asked them, "Who do you think you've been watching all this time?" He calls the other egos his "puppets" and says that this is his world. He also tells the viewers that this isn't the end of him, and he says "See you soon" as the screen cuts to black.

Anti can be heard laughing in the background of a video where Sean opens gifts from tour, but Anti does not appear on-screen.

On Halloween in 2017, Sean once again makes a pumpkin carving video. It starts with Sean in modern times, then suddenly cuts to a 1930's black and white style of video. This section of the video is silent, and Sean is dressed appropriately for the time period. The ego, known as Jameson Jackson, starts carving the pumpkin to look like his face. After a few minutes, he cuts himself and while treating the wound, Anti takes over Jameson's body. He makes the throat-slitting gesture as the words "puppet" and "SMILE" appear on the screen. At the end of the video, Jameson seemingly returns to normal and does the outro.

On December 15th, 2017, Sean started a two part charity livestream. In the first livestream, we don't see Anti, but a glitch can be seen as one of the cameras pan down to Ethan, who's on the ground. Later in the stream, a donor named "Anti" donates $300 but does not leave a message. Sean says that's "typical Anti" and as the stream ends, he makes a comment about weird things having happened in the studio earlier that day.

Then the second livestream. Antisepticeye hijacked the livestream at 10 pm GMT on December 15th and it lasted until 6pm on December 16th. This stream was dubbed as "Overnightwatch." After leaving the stream overnight—where Anti included creepy sounds and glitches—Sean and the others come back to finish the stream. The alphabet on the wall now reads "ANTI," and while Sean is changing Anti from the Bio Inc. video appears in the window. Not long after, though, Sean comes back and notes the unusual tension in the air. Later, while opening gifts that are to be donated to charity, Ethan opens a gift to him and finds it's a decapitated teddy bear. It's noted that the cut looks like it was done with a knife. Once again, later in the stream, there's a donation, and the message says they "love Jack, Robin, and Anti." Sean asks who Anti is, and Robin shows him the window where he appeared before. Sean remembers and refers to Anti as "the knife lover." Fans watched the livestream for over 24 hours just to catch the appearances of Anti, even though they took hours to appear.

Anti makes small appearances in videos in early March and early May of 2018. The appearances go as follows: in "BABY GOT BACK | Baby Hands VR (HTC Virtual Reality Wireless)" Anti says "Where is he?" in the background (can't be heard without audio enhancement); in "WATCH THIS WITH THE LIGHTS OFF" Anti appears in the computer monitor in-game; in "Barry Has A Secret" after Sean finds a toy at the end of the video, Anti appears, looking like Sean, and tells him, "You weren't supposed to find that," and then he grabs Sean while the screen fades to black; and finally, in "THEY ARE LISTENING | Stories Untold — Chapter 2" Anti appears at the end of the video, glitching in between flashing lights.

Now, technically this next appearance isn't by Anti, but it's speculated that he has something to do with them. In the video "THEY'RE HERE! | Stories Untold — Chapter 3" at the end of the video, after the screen cuts to black, a voice says, "Jack! This is Chase. You need to wake up." The next day in "IT WAS ALL CONNECTED | Stories Untold — Chapter 4" again at the end of the video, we see Sean in bed tossing and turning. Then he wakes up, looks at the camera, and says, "I remember what he did to me."

On May 9th, 14th, and 16th of 2018, fans start noticing weird behaviors from the characters. In "Try To Fall Asleep!" (May 9th) fans speculate that Sean isn't who they're watching play, as he doesn't do the intro or outro, and has played a lot of horror games as of late. Then in "Dark Silence" (May 14th) once the gameplay is over, viewers see Chase Brody in the dark flicking on a lighter. He searches through the house and then goes upstairs, and finds a hallway bathed in red light. Anti is there with his back to Chase. Chase yells at him, saying, "Who's there? Where are they? What do you want from me?!" Then Anti turns around, grins, and walks towards him. The video cuts out. Then, in "EXPLORING AN ABANDONED HOSPITAL | Exiles" Sean glitches into the frame, out of breath and confused. Then near the end of the video, as he's doing his outro, Sean cuts himself off and stares at the camera as bloody tears roll down his face. In the background, whispers saying, "It's all your fault" can be heard. The outro is glitched as well.

From here on until the end of the year, several videos have shown glitches and signs that Anti is around. These are the rest of the videos from 2018:

—August 3rd, 2018, "HOW DID HE GUESS THAT!?"

The camera glitches after Sean reads the question "Has your character killed anyone?" He says he's dug himself a hole and then it cuts to another question. Later, Sean refuses to answer the question "Is your character a puppet?" After the outro song, distorted frames of Sean screaming are seen while Anti's laughed, distorted and slowed down, plays. The waveform of this section spells out "SOON."

—August 5th, 2018, "WHAT AM I EVEN PLAYING?! | Eggs For Bart

After the outro, audio of "I will return when you least expect it" is played in reverse. The waveform of the audio is in code, and when decoded, says "DEATH."

—September 25th, 2018, "WHAT THE HELL HAPPENED? | Transference

The title of this video was changed numerous times in the Zalgo font before settling on the current title. When translated, the Zalgo font titles spelled out "HELP." In the video, four Anti glitches were spotted.

—October 14th, 2018, "3 SCARY GAMES, 1 VIDEO #7

Once again, four glitches were seen in the video. One glitch showed half of Sean's body to be green, only for a second. As Sean spoke here, his voice is distorted and he says, "Time to take off the mask."

—October 20th, 2018, "THIS GAME SCARED THE **** OUT OF ME"

Two glitches appear in the video.

—December 1st, 2018, "TIME IS BROKEN | Umfend"

The camera glitches twice, and the second time the glitch happens Sean says, "Do you remember?"

—December 7th, 2018, "WAIT FOR THE ENDING | Sally Face — Chapter 4"

The ending animation of this video is glitched.

—December 16th, 2018, "QUIT THE GAME TO WIN"

Sean tells the viewer in order to win, they must exit out of the video. And then he stares at the camera. The closed captions claim that Anti is present as Sean talks, and after this, Sean's eye twitches. It was realized that the twitches were in morse code, and it spells out "ANTI WINS."

In January and May of 2019, small hints about Anti's presence appear in videos, but nothing major. The camera will glitch, and the outro will change, and the whiteboard in the background will change. In one video in particular, uploaded on May 21st, 2019, Sean vanishes from the frame as static starts playing.

On May 23rd, 2019, the end of the video shows Sean's face-cam sliding out of view, then he says, "It's all coming together!" Then his glitches back into frame and says, "Time is all broken."

On May 24th, the video ends with Sean glitching, and then the words "Bring him" appear on-screen. Then the intro repeats itself. On June 3rd, in "How High Will My Heart Rate Go Playing Five Nights At Freddy's VR (FNAF VR)," Sean says that he's still alive and his heart is still beating. Then the screen fades to black and shows his heartrate as 0, and then the screen glitches.

In the video "I Quit YouTube For This," Sean looks down at the floor while playing a game, then looks up slowly and says, "Do you ever feel like there's something more?" Then he smiles creepily. Later, Sean feels like he's being watched and one of the cut-outs behind him glitches. Later on, the camera becomes grey with red details.

On October 13th, 2019, in the video "CHASE," as the title character searches for a picture in the glove compartment of his car, Anti can be seen in the backseat. It's largely thought that this means that Anti is the source of Chase's problems and his depression.

On Halloween, the video "Jameson Jackson's Jolly Jaunts" was uploaded. In the video Jameson performs in a puppet show, but is soon possessed by Anti. Jameson's body screams and tears at the strings, much like how Sean slit his throat in "SAY GOODBYE." Then Jameson stares at the camera, and it cuts to black.

The final appearance of Anti in 2019 is in the video "You Said We Could Be Friends... | 3 Scary Games" uploaded on November 28th. While playing the last game, towards the end of the video, the screen goes black for a few seconds, and when the screen comes back, one of Sean's lights are out. He gets frustrated very easily now, and it continues on. He becomes frustrated, then he starts pleading, and then he gets angry all within a few seconds. Sean breathes into the microphone, irritated. Then he says, "That's it. That's it, I'm coming over." Sean stares at the camera, then lunges at it. It's believed that he was possessed by Anti during this.

The next time anything Anti-related happens is on January 2nd, 2020 in "Having A Heart Attack | 3 Scary Games." Glitches appear in the video, but the cryptic messages at the end are what piqued people's interest. The messages are "Not long now" and "He's coming." An "A" appears in the window, hinting that it's Anti.

On January 16th, in "These Scares Almost Killed Me | 3 Scary Games" Sean's chair moves on its own. It's also noticed that Sean speaks in Anti's voice when he says, "It's all easy when no one knows you exist." Sean can also be seen cutting himself off and banging his head on the whiteboard while static plays, and white flashes in the video were noticed to correlate to morse code. Deciphered, it says IMHEREFRIENDHI.

On February 26th, a video, first titled "Don't Trust These Games" but currently titled "Sentient," was uploaded with Anti somewhere in the thumbnail. It was then realized that each game Sean played has to do with obeying something higher up.

In videos uploaded on March 4th, April 10th, and April 19th where it's noticed that Sean is acting out of character. He doesn't do the intro and his camera glitches occasionally. In the video uploaded on the 19th, a 3 Scary Games video, a TTS voice says, "Jack can't answer the phone right now." Again, when Sean leaves the frame a robotic voice speaks, and when deciphered, it says, "Help. They've broke me." A transcription at the end of this video translates to, "Who's this then?//It never ends will it?//Please save my friend.//Phase Two will happen."

Then, on May 1st, 2020, Sean uploaded a video originally titled "DON'T COME TO THIS HOUSE (please stay away) | The Open House" but the title was later changed to "WELCOME TO MY HOUSE (please stay away) | The Open House." One of the comments is from Sean, which says "OFFER ACCEPTED" in the Zalgo font. It's believed that this is Anti accepting an offer from another ego. Later in the video, Sean says "I'm the offer. I was the sacrifice," and it's believed it has to do with what Anti wrote in the comments. Just as the game says "Offer accepted, expect a call soon" Sean gets a call on his phone. This also may correlate to the comment.

The most recent sighting of Anti on the jacksepticeye channel was on Halloween, in the video "Don't Make Eye Contact." It was originally titled "Argentum Inanis" and the video follows Marvin the Magnificent, another ego, as he does some kind of black magic. He touches a glass ball and sees visions of other egos, such as Anti, Chase, and Dr. Schneeplestein.

We are currently unable to tell what Anti's plans are—given that it's been so long since he's made a direct appearance in a video, and he's been hiding behind glitches and cryptic messages, we have no idea what he's planning.

When he will strike is, unfortunately, unknown.