Top Ten Hardest Undertale Bosses


The Top Ten

1 Sans 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 more.

Look at his attacks! Unless you are a extreme boss, this boss is the hardest times about ten!

Lol whoever wrote ode to sans is hilarious

Best and Hardest boss in the game

Asriel? You can't even DIE in his fight!
O.Flowey? He has checkpoints!
Sans? Yeee boi!
HARD MODE Sans? Godzilla on Gatorade.

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

How is this fight hard? You can't even die in it!

What? This is not even that hard. Omega Flowey is WAY harder.

3 Omega Flowey

Looks like the hardest boss ever (tied with sans) because it's so powerful imagine a talking attracting deadly flies swinging cactus hands and shooting barrages of seeds all at once. Well good luck on that one because its pretty damn hard

Sans on hard mode is one hell of a boss, but Omega Flowey on Hard Mode is NUTS! X( I don't think anyone has beaten this boss on Hard Mode. - Doge4lifeGaming

Dear lord this is a true nightmare hands down the scariest thing or event in undertale he is also my favorite boss because it sticks out

Sans on hard mode is one hell of a boss, But Omega Flowey on Hard Mode is NUTS! X( I don't think anyone has beaten this boss on Hard Mode.

4 Asgore Asgore 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 more.


5 Mettaton 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!"


6 Undyne Undyne Undyne is a main character in Toby Fox's 2016 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, more.
7 Undyne The Undying

Why is she at number 7 I have beat all these bosses but she has to be the 2nd hardest

This is one of the TRUE heroes of Genocide. Screw you Chara-possessed-Frisk.

Probably 2nd hardest honestly

Dang, man. I'm currently stuck at this unbeatable fish! She's like, second hardest! Asriel's battle is nothing! We can't even die in it. And omega flowey, those act and green healing things are just helping us to not die! The regular undyne is easy! And also mettaton! Well, asgore is... the third? Yeah whatevvah, undyne the undying is second hardest! Ngahhh!

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8 Papyrus 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 more.
9 Muffet 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.

This boss was so hard to beat for me. Sure not as hard as undyne the undying and sans but this is harder than papyrus and undyne and mettaton EX!

10 Ruins Dummy

This is the hardest boss no doubt. The rock in the ruins might be tougher to beat though.

How do you beat this?

Sans trembles before the Ruins Dummy.


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The Contenders

11 Toriel Toriel Toriel is a main character in Toby Fox's 2016 RPG, Undertale. She is an amazing blend of goat and mother.
12 Mad Dummy

On him rn and it is so frustrating

13 Froggit

Hardcore, I was stuck on them for a very long time. He wouldn't turn yellow, and I was so confused


14 Seven Human Souls
15 Napstablook 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.

Can't kill a ghost

Don't cheer his dapperblook...I DARE YOU

16 Alphys NEO
17 Mettaton NEO Mettaton NEO

SO EASY - coolgamert

18 Lemon Bread

Took me a few tries to beat this one

19 Jerry
20 Whimsun
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List StatsUpdated 19 Oct 2017

200 votes
22 listings
1 year, 94 days old

Top Remixes

1. Asriel Dreemurr
2. Sans
3. Omega Flowey
1. Sans
2. Omega Flowey
3. Asriel Dreemurr



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