Last reviewed on 2026-05-02
Sans
The JudgeThe lazy, pun-loving skeleton who seems like a harmless comedian — until the Genocide route reveals him as the game's most terrifying final obstacle. Sans judges the protagonist's LOVE and EXP, and his battle — the hardest in the game — is a philosophical confrontation about consequences. "It's a beautiful day outside..." remains one of gaming's most chilling monologues.
Papyrus
The Great PapyrusSans's enthusiastic, scarf-wearing brother who desperately wants to join the Royal Guard by capturing a human. Papyrus's over-the-top confidence and signature Nyeh Heh Heh laugh mask a genuinely kind heart — he refuses to hurt the protagonist and believes in their goodness even when they've given him no reason to. His death in the Genocide route is the game's most heartbreaking moment.
Frisk
The Fallen HumanThe eighth human child to fall into the Underground — and the player's avatar. Frisk is deliberately a blank slate, their silent determination allowing the player's choices to define the narrative. The distinction between Frisk (the character) and Chara (the first fallen human) is one of Undertale's most debated and meaningful thematic splits.
Toriel
The Caretaker of the RuinsThe warm, pie-baking boss monster who takes Frisk under her care in the Ruins — and whose boss fight is the game's cruelest trick on first-time players. Toriel's grief over losing previous children, her complicated history with Asgore, and her genuine love for the protagonist give Undertale its emotional heartbeat from the very beginning.
Undyne
Captain of the Royal GuardThe fierce, anime-obsessed fish monster who leads the Royal Guard and relentlessly pursues Frisk with her spear. Undyne's passionate intensity and willingness to die for her beliefs make her one of the Underground's most inspiring figures. Her friendship arc with Alphys, her spaghetti cooking lesson, and Undyne the Undying in Genocide all reveal different facets of her unbreakable spirit.
Alphys
Royal ScientistThe anxious, anime-loving royal scientist who created Mettaton and conducted the horrifying amalgamate experiments. Alphys's insecurity, her guilt over her laboratory's secrets, and her crush on Undyne make her the game's most internally complex monster. Her True Lab — revealing the cost of her experiments — is Undertale's horror sequence, and her character development in the True Pacifist route is deeply earned.
Flowey
The Flower / Asriel Dreemurr"Howdy! I'm Flowey. Flowey the Flower!" The cheerful flower who immediately tries to kill Frisk — and whose reveal as the fallen prince Asriel Dreemurr is Undertale's central emotional mystery. Flowey's nihilism — born from losing his soul and spending eons resetting the world out of boredom — is the game's philosophical core. His final form as Omega Flowey and his True Pacifist restoration are the game's twin peaks.
Mettaton
Underground TV StarAlphys's flamboyant robot creation — a ghost who always wanted to be a star, now inhabiting the body built for him. Mettaton's increasingly elaborate show-stopping segments are some of Undertale's funniest encounters. His EX form and his final monologue — revealing he genuinely cares about the monsters he pretended to endanger — give his arc unexpected heart.
Asgore Dreemurr
King of the UndergroundThe gentle, tea-loving king whose grief transformed him into the final obstacle standing between humanity and monster-kind. Asgore's tragic decree — collect seven human souls to break the barrier — was made in a moment of despair and has haunted him ever since. Fighting him feels fundamentally wrong; his final moment in the True Pacifist route, finally given a chance at happiness, is quietly devastating.
Chara
The First Fallen HumanThe first human to fall into the Underground — Asriel's adoptive sibling and the vessel for the Genocide route's final revelation. Chara's true nature remains Undertale's most debated mystery: were they always evil, or are they simply what the player's choices call forth? Their direct-address ending speech — acknowledging that you wanted to destroy for fun — is among the most unsettling moments in game narrative history.
About Undertale
Undertale was created by Toby Fox and released in September 2015 after a successful Kickstarter campaign. Made almost entirely by Fox himself (with some art assistance from Temmie Chang), it became one of the most critically acclaimed indie games of its era.
The game is celebrated for subverting RPG conventions — rewarding pacifism, breaking the fourth wall, and making every character's life feel meaningful. Its music, composed entirely by Fox, includes tracks like Megalovania that have become part of internet culture. Deltarune (2018–), a companion project by Fox, revisits many characters in a parallel universe.