1 Secretly the most badass character in the game (Sans)
Whoever thinks it's the worst... You're gonna have a bad time.
Sans haters are gonna have a bad thyme. It was TEMpting. SO SORRY for not being able to LIFT YOUR SPIRITS.
The reason says it all.
It makes SANS to vote for him.
2 True Lab Plot Twist (Alphys)
3 So innocent that he still believes in you even after having his head chopped off by you (Papyrus)
He should be number one, He's so sweet.
His belief in you seems to never disappear...even when you're a genocidal monster that killed all his friends, decapitated him and plans to destroy the entire underground and timeline.
4 Literally unable to do anything without putting MAXIMUM power into it (Undyne)
5 Having literally the best dog ever (Alphys)
6 Generally being the cutest animal to ever walk the earth (Temmie)
7 Essentially Luigi and Skeletor fused together (Papyrus)
8 Generally being the cutest girl to ever walk the earth (Alphys)
9 Being able to live out his entire life without even having arms (Monster Kid)
10 Having the world's most adorable lesbian crush on each other (Alphys and Undyne)
11 Jokes so bad they're good (Sans)
His jokes brought laughter into my dark life. If this isn't a reason to love this character so much, I dunno know what is.
12 His name (Heats Flamesman)
13 The True Pacifist Ending (Asriel)
14 His cloyingly adorable former marriage with Toriel (Asgore)
15 Frequently portrayed by fans as having a posh British accent (Gaster)
16 Being portrayed as a female version of Ren Höek in the fanfic Alphys Höek (Alphys)
17 So much of a douche that it's literally hilarious (Mettaton)
18 Some of the greatest character designs ever created...by Cthulhu (The Amalgamates)
19 Still a cute and playful puppy at heart (Endogeny)
20 Flextraordinaire (Aaron)
21 Smelling like sweet lemons (Lemon Bread)
22 Those facial expressions (Temmie)
23 THOSE facial expressions (Burgerpants)
24 Looking like a character pulled straight out of Ren & Stimpy (Burgerpants)
25 Literally hand-drawn in Microsoft Paint (Burgerpants)
26 Based off of a certain Kickstarter backer that donated a crapload of money for the game's development (So Sorry)
27 Literally the in-game representation of Toby Fox himself (Annoying Dog)
28 THEM legs (Mettaton)
29 The closest thing we currently have to David Bowie (Mettaton)
30 That glowing eye (Sans)
31 Small puppy, GINORMOUS suit of armor (Greater Dog)
32 Dog marriage (Dogi)
33 THAT neck (Lesser Dog)
34 Gives you the option to ditch him whenever you want (Jerry)
35 That hat (Ice Cap)
36 Looking by far the cutest as a Tsum Tsum out of all the characters (Alphys)
37 The mystery (Gaster)
38 His raging "boner" for spaghetti (Papyrus)
39 Being the only monster that doesn't kill you when you lose to him (Papyrus)
40 You get to call her Goat Mom (Toriel)
41 Finally firing Alphys from her former job as the underground's Royal Scientist (Toriel)
42 Literally having a hedge trimmed in the shape of his smile (Papyrus)
43 Being literally too lazy to even pick up his socks off of the floor (Sans)
44 The Brock Face (Frisk)
45 Dora Hair (Frisk)
46 A true pacifist in a world where everything is trying to kill them (Frisk)
47 Being the most demented and psychotic child to ever walk the earth, having chubby rosy cheeks in the process, and most importantly being proud of it (Chara)
48 Literally a tsundere plane (Tsunderplane)
49 About the closest thing to a Mimiga in Undertale (Asriel)
50 Omega Flowey (Flowey)