Hardest Undertale Fights

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 boss fight, bad puns, and the phrases "geeetttt dunked on!!!" and "you're gonna have a bad time." He is also named after the font "comic sans." Known for also being Ness from the Mother series. (known as Earthbound in Western territories.)

He avoids all your useless attacks. He is the one who knows that you are an anomaly other than flowey, alphys, and Gaster

Sans kicks your ass he 1 4 sure

Undertale sucks.

Very hard or not?

2 Undyne (Genocide)

Undyne is a fish who appeared in the 2015 RPG Undertale made by Toby Fox. When you take the Geoncide route she gets angry that you kill all of her friends and instead of fighting normal Undyne you have to fight a way harder version. The reason this fight is hard is because her spears fly at you really fast and they have hundreds of various patterns.

You're gonna have to try a little harder than THAT.

I'm legit still stuck on this battle

Genocide myself

3 Omega Flowey

This is bullet hell played straight.

The horrible abomination...

4 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 at throughout the players journey and his fate at the end of the game is determined by the choices the player has made.

I was stuck on this battle for months and months...

5 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 not kill a single character. As a young child, he was a close friend of Chara, a human child who... read more
6 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 a super duper hard battle, like wow. Maybe sans is harder but I only go pasifact

7 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.
8 Undyne (Pacifist) 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, King Asgore, her best friend, Papyrus, and her love interest, Alphys.

Yeah, first time it's pretty tough...

9 Lemon Bread
10 Dummy

I think you mean mad dummy which is why I voted

This game sucks, Dummy!

The Contenders
11 Froggit
12 Alphys NEO
13 Jerry

I rage quit Undertale for 1 month after losing to Jerry 70 times. I was playing Undertale for 3 hours trying to beat Jerry. I have now come back to Undertale on a genocide route and I am stuck on Mettaton NEO.

14 Pacifist Credits
15 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.
16 Mad Mew Mew

This battle is challenging, especially if you're trying to do no hit

17 Mettaton NEO
BAdd New Item