Frisk is a yellow-skinned human child who wears a long-sleeve light blue shirt with two magenta stripes, light blue pants (often depicted as shorts in the official Undertale merch), and red-brown shoes (usually depicted as black or in a darker tone). They have medium-length straight red-brown hair, short and choppy bangs, and a blank expression. Though Frisk does not show much expression in the overworld, NPCs often describe Frisk's expressions.[1] Just like the first human, they have no stated gender[2] and are solely referred to with "they/them" pronouns throughout the game,[3][4] or by generic terms (such as "child", "human", or "kid".)

[NO MIND THE VOICE] Sans appears as a relatively short and paunchy skeleton, with mitten-like hands. Sans is always seen with a wide, toothy-grin on his face. Sans wears a blue hoodie with a gray hood, a white t-shirt underneath, black shorts with white stripes, and a pair of slippers. He has white dots for pupils in his black eye sockets that disappear when he is serious or angered. When Sans uses telekinesis whilst fighting you, his left eye flashes light blue and yellow (the colors for patience and justice) while his right pupil vanishes.

[BRO I DON'T CARE ABOUT VOICE PLS YOU TOO-] Flowey is a sentient golden flower. He has a white center, six yellow petals, and a light-green stem. Flowey can show a variety of expressions and can mimic the faces and voices of other characters. He mimics Toriel and Asgore in some situations, as well as his old self at the end of the Genocide Route. He also mimics the protagonist's face before the Neutral Route's final battle

[DON'T MIND VOICE PLS] Nine is a doppelgänger of his mainstream counterpart, albeit with some notable differences. As such, he is a young, anthropomorphic fox with a unique genetic mutation, giving him two tails instead of one. He possesses dull amber fur with white fur around his muzzle, front torso, and the tips of his tails, and he has fluffy fur at the tips of his cheeks and chest. He also has large triangular ears with white canals and furry orange ends split in two on top of his head, sky-blue eyes, a small black nose, and three upturned locks of hair on his forehead. Unlike his mainstream version, the fur of Nine's tails aren't fluffed out, making them appear thinner. He is also one of the only variants that is fully clothed, the others mostly wearing just gloves and shoes