Napstablook

Napstablook is a melancholic ghost monster and musician who lives in Waterfall. They are encountered in the Ruins as the game's first miniboss.

Personality
Napstablook is a very dour individual, with low self-esteem and an introverted attitude. Despite this, they're shown to be courteous to others, such as treating the player as a guest in their home, and often blaming themself and apologizing for inconveniences to be polite.

Neutral and True Pacifist Route
The player first finds Napstablook blocking their path in the the Ruins, pretending to be asleep. Once the player cheers them up, they will cry themself a nice hat, calling the trick "Dapperblook". They will thank the player for being so friendly and then leave.

If the player did not attack them in their fight, Napstablook next appears in the Ruins' six-holed puzzle room, in its center-bottom basement room. They say, "i fell down a hole... now i cant get up... go on without me... wait, ghosts can fly, can't they... oh well..." They fade away afterwards, presumably to return to their house in Waterfall. (It is notable that a monster says elsewhere that it is said that only spiders and ghosts can travel in and out of the Ruins.)

Napstablook does not appear again until much later, when the player is fighting the Mad Dummy in the Waterfall's Garbage Zone; they interrupt the fight by crying on the Dummy until they run away. Napstablook apologizes for breaking up the "fun" the player was having and welcomes them into their house, which is just east of Undyne's. From this point on, Napstablook wears headphones. In their house, you can listen to their music and they will tell you they are working on a mix CD. You can also try to eat a ghost sandwich with Napstablook, but after you are unable to eat it, Napstablook suggests that the two of you lie on the floor together, and that this is a family tradition. If you choose to lie down, after some time the music and background will change into relaxing space scenery. They have three playable CDs: Spooktune, Spookwave, and Ghouliday. If the player is listening to any of the CDs when they leave Napstablook's house, it may trigger an event where Aaron and Woshua encounter the player, but are turned off from fighting due to the frightening music.

Later during the Mettaton fight, Napstablook is the first viewer to call and express their gratitude for the program, saying they watch the program all the time.

True Pacifist Route Ending
Napstablook is seen outside their house with Mettaton, having been recruited as the celebrity's sound mixer. They reveal that they were not absorbed by Asriel because when the light of Asriel knocked on their door, they just closed the blinds and continued mixing music. As a result, they initially didn't learn Frisk's name. In the credits, Napstablook is seen on tour with Mettaton and Shyren.

Genocide Route
If the player has killed all of the possible monsters before their encounter, Napstablook will simply fade away when the player approaches. Later on, Napstablook does not intervene in the Mad Dummy fight as they normally would; instead the scene ends on its own.

Snail Farm
East of Napstablook's house is a snail farm owned by Napstablook's family, where they are the remaining worker. Here, you can participate in a snail race for 10 g. By encouraging your snail as it crawls across the track, the snail will go faster. But too much encouragement can cause it to light on fire and encouraging it too little makes it believe their best wasn't enough. If the player manages to win the race, they only receive 9 g back as Napstablook needs to make a profit. If the snail loses by a slim margin, Napstablook will observe that the snail will think it won and will give you 30 g in order to be polite and not hurt its feelings.

Attacks

 * Napstablook starts crying, the tears falling straight down.
 * Napstablook starts crying long, wiggly tears that change direction upon approaching the walls, eventually falling back down towards you once they are above you.
 * Harmless grey text that says "REALLY NOT FEELIN UP TO IT RIGHT NOW. SORRY."

Strategy

 * After selecting the ACT 'Cheer' twice, Napstablook shows the player their "Dapper blook" trick; they start crying again, but the tears move upwards to form a top hat on their head. Napstablook then stops attacking, awaiting the player's response.
 * Selecting 'Cheer' or 'Flirt' will peacefully end the battle.
 * Selecting 'Check', 'Threat' or attacking with FIGHT will make Napstablook extremely sad. In this state, Napstablook's attacks begin to involve an absurd amount of tears. After 6 turns of cheering up, the attacks lower in intensity. After 8 turns of cheering up, Napstablook returns to their normal state. It is then possible to cheer them up some more and end the encounter peacefully.

True Pacifist Ending Credits

 * White Text - "?"
 * Yellow Text - " Spooky DJ "
 * In order to acheive yellow text, it must be spared.

Quotes

 * oh, i'm REAL funny. [Check]
 * nnnnnnggghhh. [Neutral]
 * just pluggin along... [Neutral]
 * i'm fine. thanks. [Neutral]
 * i'd just weigh you down. [Flirt]
 * go ahead, do it. [Threat]
 * heh... [Cheer]
 * heh... heh... [Second Cheer]
 * let me try... | i call it "dapper blook" | do you like it? [Third Cheer]
 * i knew it... [Check/Fight/Threaten after showing a top hat]

Flavor Text

 * This monster doesn't seem to have a sense of humor... [Check]
 * Missed the memo and is the same difficulty as normal. [Check in Hard Mode]
 * Here comes Napstablook. [Encounter]
 * Here comes Napstablook. Same as usual. [Encounter in Hard Mode]
 * Napstablook is wishing they weren't here. [Neutral]
 * Napstablook is staring into the distance. [Neutral]
 * Napstablook is pretending to sleep. [Neutral]
 * The faint odor of ectoplasm permeates the vicinity.  [Neutral]
 * You gave Napstablook a patient smile. [Cheer]
 * Napstablook looks just a little bit better. [Cheer]
 * You told Napstablook a little joke. [Cheer]
 * Cheering seems to have improved Napstablook's mood again. [Cheer]
 * Napstablook wants to show you something. [Cheer]
 * Napstablook eagerly awaits your response. [Cheer]
 * You give Napstablook a cruel look. [Threat]

Trivia

 * Napstablook's name seems to be a reference to the file-sharing software Napster, whose logo is a cat wearing headphones. Napstablook is seen wearing headphones in their house, and inspecting their computer says they're on a music-sharing forum. This could also explain the similarities between some music in the game.
 * Napstablook's name could also reference the player's first encounter with them. In the Ruins, Napstablook is found sleeping directly in the player's path, with no other way around them. That is - they nap to block you.
 * Due to dialogue from the Mad Dummy, it is implied Napstablook's tears feel like or are composed of acid rain.
 * Naming yourself Napsta or Blooky will get the message "............ (They're powerless to stop you.)"
 * Napstablook and the Dummy are the only enemies in Hard Mode that never changes in difficulty, due to missing a memo regarding Hard Mode.
 * By simply ignoring the light to go back to mixing their music, Napstablook is the only monster whose soul wasn't taken during Asriel Dreemurr's absorption process.
 * Napstablook used to work with their cousins at the snail farm before they went off on their own to gain a corporeal form. Their story is expanded upon if you enter the house next to Napstablook's, which can be unlocked with the Mystery Key that can be bought from Bratty and Catty. The cousin who lived next-door to them is heavily implied to be Mettaton, with one unnamed cousin going off to become training dummy.
 * If you Check/Fight/Threaten after Napstablook shows their top hat, their attacks increase in intensity. After 6 turns of Cheering, it lowers in intensity, and after 8 turns, Napstablook turns into their normal state, becoming able to end the encounter in a friendly way.