Flowey

 is the first character encountered in Undertale. He provides an introduction to the mechanics of encounters by "sharing friendliness pellets", which are actually harmful bullets. He attempts to mislead the protagonist by urging them to take a violent approach throughout their journey in the Underground.

Appearance
usually takes on the appearance of a sentient, grinning, golden flower, with a white androecium, 6 yellow petals and a green stem. is able to contort his face dramatically into a variety of different expressions, sometimes even mimicking the faces and voices of other characters (Such as Toriel and Asgore in some situations).

Personality
Initially, operates under a facade of friendliness and politeness. He has a habit of greeting the protagonist with "Howdy!", calling himself "your best friend," and, like his father, appending polite words such as "gosh" and "golly" to the ends of his sentences. Whenever he drops this guise of friendliness, he also has a habit of calling the protagonist an "idiot". His central philosophy is that "In this world, it's kill or be killed."

As shown throughout the game, has a generally malevolent and cruel disposition, regularly berating a pacifist protagonist for ignoring his kill-or-be-killed advice and generally talking about his desire to destroy the world. He is a cunning planner and subtle if the circumstances require it, even manipulating the protagonist into bringing him as many monster SOULs as they can find in the neutral ending. He is notably able to retain his memories between SAVEs (having once had the ability to do so himself). He also possesses a disturbing sense of humor, as shown in his boss fight, in which he turns into "Photoshop ", or "Omega " as dubbed by fans.

Main Story
first appears at the start of the game, and provides a tutorial of sorts. He urges the protagonist to run into his "friendliness pellets." However, if the protagonist runs into these "pellets," which are actually bullets, announces his "kill or be killed" attitude to the protagonist. Alternatively, the protagonist can dodge his bullets up to three times, which causes his act to gradually slip, until he hypocritically snaps at the protagonist for toying with him. Either way, will then proceed to surround the protagonist in an inescapable ring of bullets which close in on the protagonist. However, this attack is prevented by the timely arrival of Toriel.

Ruins Exit
At the exit to the Ruins, reappears to judge the protagonist's actions up to that point.
 * If the protagonist spared Toriel, then calls them "clever", but reminds them that they only spared a single person's life:
 * If the protagonist has killed any other monster, he lists the names of every killable monster in the Ruins and points out that every one of them may have had families and loved ones, regardless of which enemy types the protagonist has killed or how many they have killed. He calls the protagonist a selfish brat and says: "Somebody is dead because of you."
 * If the protagonist did not kill anybody, and has never killed Toriel, speculates that if they meet a "relentless killer", they will be killed repeatedly until they eventually give up;  wonders if they will either kill out of frustration, or if they will quit the game entirely, leaving control over the world (through the ability to SAVE, though this is not stated) to . He tells the protagonist that he won't kill them, and instead will watch them struggle through the rest of the Underground.
 * If the protagonist had killed Toriel at least once before, then reset or loaded the game to spare her, tells them not to get cocky and proceeds to taunt them by pointing out what they had done: "You murdered her. And then you went back, because you regretted it." He informs the protagonist he previously had the power to SAVE and reset, and that he played as the world's god before the protagonist's arrival superseded his. He tells the protagonist that he will be watching them.
 * If the protagonist killed Toriel:
 * If the protagonist killed Toriel once and hadn't gotten past her before that point, mocks Toriel for trying to save the protagonist when she ultimately couldn't save herself.
 * If the protagonist kills Toriel, reloads the game, and then kills her again, calls the protagonist a "disgusting animal" for not even trying to spare her.
 * Repeated kills will have him question how many times the protagonist will continue to do this.
 * If the protagonist had spared Toriel once before, then killed her, calls them "utterly repulsive." He remembers the protagonist had spared her life, then goes on to taunt them, saying they went back and murdered her just to see what would happen. He informs the protagonist he previously had the power to SAVE and reset, and that he played as the world's god before the protagonist's arrival superseded his. He tells the protagonist that he will be watching them.
 * If the protagonist has met the requirements to begin the Genocide Route, questions if they are really human. He sees a kindred spirit inside them - Chara. He tells them of his plan to become all powerful and destroy everything in the world together.
 * If the protagonist has completed the game once before, won't appear at all.

Neutral Route
After the Ruins, will be seemingly absent from the remainder of the game until the end of the encounter with Asgore. However, there are several moments throughout the game where if the protagonist backtracks, can be seen at the edge of the screen, before he rapidly disappears into the ground.

If the protagonist decides to backtrack around a vertical room with several Echo Flowers and a sign about the "fallen angel" in Waterfall, he will leave a message to the echo flower closest to him. He will either taunt the protagonist about how Toriel will forget about them and find another child to take care of, or remind the protagonist about how she's trapped in a cold, dark void with nobody to rescue her depending on whether the protagonist has killed her or not.

At the end of the fight with Asgore, if the protagonist decides to kill Asgore, will appear, and absorb the six bottled human souls. If Asgore is spared, will appear nevertheless, and kill Asgore himself.

After this occurs, the game will suddenly close. Upon relaunching the game, the intro seems to play as normal, however the Boss Monster is replaced with a Loox, and the intro cannot be skipped. Suddenly, the text "One day, war broke out between the races" will be replaced with "One day, they all disappeared without a trace", the screen seems to glitch, and the title of the window rapidly changes between random sets of letters.

The protagonist will be plunged into a black void, and the game window will now be "Floweytale". If the protagonist continues upward, they will find a SAVE point. Upon interacting with it, it opens Flowey's SAVE file entitled "My World", which has the LV 9999 and play time as 9999:99.

After this SAVE file is opened, will appear, destroy it, and gloat, stating that because of the protagonist's idiocy, Asgore is dead, and  now possesses the six human souls. He states that once he absorbs his seventh SOUL—the protagonist's—he "will become god," and he will teach monsters, humans, and everyone else the "true meaning of this world": kill or be killed.

After this, an encounter with Photoshop occurs. This battle is not RPG-oriented; instead, it is entirely a bullet-hell encounter. As the battle progresses, the protagonist manages to call for help from each of the six souls. After doing so, the souls reduce 's defense to zero, which allows the protagonist repetitively attack Photoshop until 's health drops to zero. After doing so, will reload the save file to an alternative slot, and gloat about their power. He then will repetitively kill the protagonist, and reload, before finally deciding to save over their death. However, before Photoshop manages to do this, the souls manage to revolt against Photoshop, and defeat him.

After this, one of the Neutral Endings will occur. Then, will reappear, and advise the protagonist on how to get a better ending. If the protagonist had gone through the game killing enemies,, believing his "kill or be killed" philosophy may be meaningless, will ask the protagonist to prove it to him by playing the game again without killing anyone; he then promises not to kill the king and will give the protagonist their "happy ending." If the player then resets the game, will remind them to make friends with everyone, skipping the tutorial "fight", and 's post-Toriel dialogue entirely.

If the protagonist had spared every single enemy, yet they have not met all the requirements for the True Pacifist Route, he mentions that maybe the protagonist could get closer to Papyrus, Undyne, or Alphys depending on whether or not the protagonist had completed their side quests to become friends. then allows the protagonist to recover their previous save file and follow his advice.

If the protagonist kills, he will acknowledge the protagonist successfully finishing him off, before seemingly becoming a regular flower. He will not leave a message for the protagonist after credits' close, and after a reset will not appear at all until the fight with Asgore, where they will berate the protagonist for thinking that killing them solved anything, and he will explain that he was brought back when the protagonist loaded their SAVE file, and that they still cannot achieve their happy ending. He then destroys Asgore's soul. This time around, the protagonist is not able to fight, as the game leads straight to Sans' phone call.

True Pacifist Route

 * For further information, see Asriel Dreemurr.

Genocide Route

 * For further information, see Asriel Dreemurr.

Attacks
In his regular form as a mere flower, uses only two attacks, consisting of a five-bullet spread that slightly hone in on the protagonist's SOUL, and a large ring of bullets which surround the SOUL and cannot be dodged. He is able to speed up the spread, though the limits of his attacks and speed are unknown. Getting hit by his five-bullet spread reduces HP to 1.
 * See Photoshop.

Relationships

 * See Asriel Dreemurr.

Name
"Flowey" is derived from "flower". If "" is inputted for the fallen child's name, the response becomes "I already CHOSE that name" and prevents the name from being used.

Trivia

 * Dtextractionmachine.png exploring the True Laboratory, the protagonist encounters a strange machine whose form eerily resembles that of Photoshop Flowey, albeit hollow and without Flowey's extra teeth, gums, or eyes. This is the DT Extraction Machine, which Alphys used to extract Determination from the six previously captured human Souls, the same Souls that Photoshop Flowey would use to power himself.
 * During an early stage of Undertale when it was called "UnderBound 2", it was revealed that was planned to be the reincarnation of "Face" who was the protagonist of the non-existent EarthBound hack, UnderGround.
 * Along with Mettaton, Flowey is one of the only characters in the game to have a voice clip. Near the beginning of the Genocide Route, he exclaims "that's a wonderful idea!".
 * 's laugh is not an entirely new asset and can be recognized in other media such as the PlayStation title Tomba! and the soundtrack "The Lordling" also by Toby Fox.
 * At the end of the Demo, 's face disappears from the flower in the first image in the "instructions" folder. In addition to this, the final image will change to a note that reads: "A Note From Your Friend - Don't get too cocky."
 * However, if this is a genocide run, the first image in the "instructions" folder will remain the same as it was when the game was started, but all the other images will be replaced with the demo's Genocide Route ending screen, and the last image will be replaced with a faceless.
 * If the game is reset during a Genocide Route, says "Really, [name]? Well, do what you will. I'll be waiting for you," implying some disappointment or sense of betrayal. Additionally, this will skip the tutorial "fight", and 's post-Toriel dialogue entirely.
 * If a Neutral Route is completed after aborting the Genocide Route, will scold the protagonist about quitting before achieving true victory, before realizing that perhaps the protagonist wanted to see everything before they destroyed it.
 * After resetting a neutral run, or if the game is closed during the initial event with, and then reopened, 's dialogue will slightly differ; he will question if introducing himself was necessary, implying that the protagonist already knew about him, and will proceed to teach them "proper manners" and start the tutorial. Doing this again will cause to say "Don't you have anything better to do?" before starting the tutorial, which will loop if the game is restarted again.
 * If the protagonist has already fought in a timeline, fighting him again is impossible. Attempting to fight him again will make  remark that the 6 human souls would probably revolt again. Attempting to fight him a second time will have him ask the protagonist if they have "anything better to do." Attempting to fight  anymore times will leave him speechless.
 * When some certain monsters are attacked, the same sound effect when is interrupted by Toriel at the beginning of the game will play.
 * If one restarts their game after a successful neutral run, will remind the protagonist that they have to "befriend everyone this time". He will then disappear, leaving Toriel to come down and find the protagonist. When loading subsequent times,  will not show up at all.
 * has the most talking sprites out of any character in the game.
 * If the player backtracks during certain rooms of the game after meeting, they might be able to see him sinking into the ground behind them. This implies that stalks the protagonist throughout their journey underground.