Top 10 Undertale Bosses

The Top Ten
1 Sans Sans or Sans the Skeleton is a character in the 2015 RPG Undertale created by Toby Fox. He is a lazy, pun-loving skeleton who is a supporting protagonist in the "pacifist" and "neutral" routes of Undertale, and a heroic antagonist/final boss of the "genocide" route. He is known for his incredibly difficult... read more

Definitely the hardest boss in the game, probably taking at least 20 or 30 tries to beat the first time, and the one with the best gameplay, with lots of different attacks that require a lot of skill and some pretty good reflexes.

Also, Sans is one of the best characters in the game, and being forced to kill him is kind of heartbreaking, especially with all his dialogue throughout the fight. It's an emotional and stressful ride that we won't be forgetting anytime soon.

A massively powerful monster. I mean, he can throw about 1,000,000 bones, fire deadly Gaster Blasters, use telekinesis (not referring to the Pokémon move), poison you with karmic retribution, teleport, break the 4th wall, and FREEZE TIME! I rank him as the 3rd most powerful Undertale character, but he is still very carefree and lazy, telling bad puns.

I also love his battle song.

2 Mettaton Mettaton is a character in the popular 2015 RPG game, Undertale. He is a robot with a soul built by Dr. Alphys, and is the sole television star of the underground. Mettaton is a popular character in the fanbase. His notable features include his legs, and his catchphrase "OH YESSSS!"

Mettaton is probably the funniest character in the whole game, and his final battle is certainly his climax. Starring his beautiful new body, Mettaton EX is the perfect combination of fun gameplay and funny moments and dialogue. It's also one of the most creative moments in Undertale - the idea of an audience score during the fight is brilliant.

All right! I think we were all expecting Sans, but I definitely think Mettaton is the best. He also has by far the best theme song and, of course, the best legs.

3 Asriel Dreemurr Asriel Dreemurr is a character from the 2015 game Undertale. He was created by Toby Fox.

Asriel is the child of King Asgore Dreemurr and Queen Toriel, but he seemingly passed away prior to the game's events. His backstory is only focused on in the True Pacifist Route, which means the player does... read more

Top ten boss fights. Not top ten hardest boss fights. The only way to win is not by sparing him, but by saving him. His track is one of the best in the game - I'm talking about His Theme. A complete masterpiece that deserves better than to be featured in some sad comics and animations that don't have anything to do with Asriel or Flowey.

Also, he has the saddest backstory in the game, with the second being Chara. He is the most powerful boss in the entire game (he has the power of seven humans and can erase existence), and the fight is one of the most epic in the game. Saving someone who seemed irredeemable but definitely wasn't is unforgettable.

4 Photoshop Flowey

I couldn't possibly have chosen any other boss battle for the top spot. This fight is the perfect final battle for the game: it's hard, it's disturbing (whoever thought of making Omega Flowey a Photoshop abomination is a genius), it's fun, and it's EPIC on a whole new level.

The soundtrack is amazing and fits so well in the fight that it's almost like they made it first and then created a boss battle to match it! Also, making Flowey able to load save files and close your game during the fight makes it even more disturbing and scary. It's just brilliant.

It's not the most emotional fight in the game, nor does it have the best gameplay, but the whole feeling of despair and eventual epicness makes it so satisfying and memorable. The sudden change of graphics also makes it really unique.

5 Asgore Dreemurr Asgore Dreemurr is a boss monster and the king of the monsters in the 2015 RPG Undertale made by Toby Fox. Asgore is the portrayed main antagonist who plans to acquire seven human souls and use their power to break the barrier that seals the monsters underground . Aspects of his character are hinted... read more

This is a boss that is not only difficult, but it's also a pretty emotional one. He's reluctant to fight. He can't even look you in the eye. The music fills the atmosphere, his attacks weaken as your HP lowers, etc. Enough said.

The epic opening, breaking mercy, being forced to fight the kindest monster in the Underground, his final words, the bitter end. No other boss represents Undertale better than Asgore.

I legit got stuck on this battle for like a month because I ran out of food, and it's so hard without consumables...

6 Papyrus Papyrus is a character from the 2015 game Undertale, made by Toby Fox. He is the Younger brother of Sans the skeleton, royal guard in training, and a sentry in the town of Snowdin. Opposite to his brother, papyrus is active, loud, and full of himself; but in an endearing way. Papyrus means to become... read more

I truly love the Papyrus boss fight. Bonetrousle is one of my favorite pieces of music in Undertale, and it's an extremely funny fight, especially considering that his dialogue is some of the funniest.

What I truly love about Papyrus is that he refuses to kill anyone, which is one of the sweetest things in any game... EVER! Well done, Toby Fox, for creating such an original character.

I really love this boss fight because it's easy and fun! It's pretty amusing, and there are a lot of jokes in there - it gets even better if you decide to flirt with Papyrus! You don't even really need to do anything, as you can just die three times, and precious cinnamon roll Papyrus will spare you anyway. He just can't bear to hurt you, aww.

7 Undyne the Undying Undyne is a main character in Toby Fox's 2015 RPG, Undertale. She is the heroic fishlike captain of the Royal Guard, who takes it upon herself to protect the monsters of the Underground. Her name is derived from the word "Undine", and is a pun on the word "Undying". Her most loved monsters are her mentor,... read more

Here's the second hardest boss in the game, and the one who tried to warn us about how frustrating the path we were taking was going to be. The introduction to this fight is really awesome and unexpected because every other character you faced up to this point was instantly killed with one hit. But not Undyne. She just refused to die.

Let's face it. I can't vote for Sans because I haven't fought him yet. And do you know why? Because I can't get past Undyne. I mean, this boss fight is an amazing one to get stuck on, and then you just curl up into a ball of despair because you can't beat it.

8 Muffet Muffet is a character from the game Undertale. She appears in a region called Hotland, selling pastries to raise money to rent a heated limo to help the spider clan from the Ruins (who are also raising a bake sale) reunite with the one in Hotland because the spiders can't cross Snowdin.

Her song is one of the best I've heard in this game, her fight is innovative, and it's fairly challenging. Enough said.

You can even skip this battle. The YouTuber I watched skipped it, and I usually HATE spiders, but today I did some research... Best boss.

Truly amazing song and plot. Couldn't be harder or better for the game.

9 Toriel Toriel is a goat like monster who is the secondary major character in Toby Fox's 2016 RPG, Undertale. She saves the protagonist from Flowey and guides them through the Ruins, of which she is the self-proclaimed caretaker. She is the ex-wife of Asgore, the mother of Asriel Dreemurr, the adoptive mother... read more

She's definitely one of the easiest bosses, but also one of those bosses that can really pull on your heartstrings.

10 Alphys NEO
The Contenders
11 Mad Dummy

This thing just looks funny, has great music, and overall is a really fun and hilarious boss fight. I love its attacks.

I have a bone to pick with people who think Sans is the best. Awesome battle theme too.

Probably the most original fight, because you have to use his own attacks against him to beat him.

12 Undyne Undyne is a main character in Toby Fox's 2015 RPG, Undertale. She is the heroic fishlike captain of the Royal Guard, who takes it upon herself to protect the monsters of the Underground. Her name is derived from the word "Undine", and is a pun on the word "Undying". Her most loved monsters are her mentor,... read more
13 Greater Dog

All of the dogs in the game are so cute!

14 Gaster
15 Snowdrake's Mother
16 Napstablook Napstablook is a secondary character from Toby Fox's 2016 RPG, Undertale. He is the cousin of Mettaton, who left him in order to become famous. Due to this, poor Blooky has crippling depression.
17 Mettaton NEO

He attacks if there's an audience and if you do nothing in the fight.

18 Reaper Bird
19 Memoryhead
20 Chara Chara is a character in the game Undertale by Toby "Radiation" Fox who is one of the seven people to fall to the Underground prior to the fall of the player character. Their name can be changed by the player and will be assumed as the player character, until the Pacifist Route when Asriel asks for the... read more
21 Lesser Dog Lesser Dog is a character from Undertale. He is part of the Snowdin Canine Unit, and is famous for his long neck.
22 Mad Mew Mew

A psychotic training dummy has become... an anime girl? This is a happy twist for Mad Dummy (assuming you spare Mew Mew). If you talk to her later, you'll find that she's becoming more like the character she appears as, and less like, well, Mad Dummy.

23 Endogeny Endogeny is a minor character in the indie game "Undertale," developed by Toby Fox. This creature is a part of the "Amalgamates," monsters that have been experimented on and fused together. Endogeny is a disturbing blend of several dogs and is encountered in the True Lab. Despite its unsettling appearance,... read more
24 Lemon Bread
25 So Sorry
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