Undertale RPG

Mettaton has black hair with a long fringe that seems to cover his right eye, pale "skin" and visible metal segments below and above his left eye.

He has a pink chest piece, a narrow metallic waist with a box contraption, and black shoulder pads above his segmented arms, which end in gloves. The chest piece has what appear to be a speaker and some knob or gauge, while the waist has two parts that seem to act as a locking mechanism that holds his "heart-shaped core," as they both lose white pixels during his "heart-to-heart" attack. His long black-clad legs end in pink high-heeled boots.

Mettaton is a confident, charismatic, and charming TV host that loves drama, action, and violence. He lives for his ratings and adores performing. He supposedly strikes a pose when he does something wrong and makes time on his various shows to beat up "heel-turning villains." He shows a rather shallow appreciation for existence at times. He has a strong craving for attention and seems very egotistical, shown when he boasts about the beauty of his true form. However, despite his seemingly self-centered personality, he deeply cares about the seemingly positive impact his show has had on the inhabitants of the Underground.

Asgore is kind and upbeat, yet often quiet. He speaks in Southern slang, such as "howdy" and "golly".

Asgore has two large curved horns, golden-blond mane and beard, white fur, long ears, a snout, and a set of visible fangs. Asgore wears a small, three-pointed crown atop his head, golden pauldrons and a long purple cape that slightly drags along the ground, which he often uses as a cloak for his armored body. Asgore's armor consists of a large chestplate, with a winged crest of the implied "angel" from the Delta Rune emblem, and his tasset visually resembling the triangles of the emblem. Underneath is a standard outfit, consisting of pants and a shirt, though only the shirt's collar can be seen in color.

Alphys is a short, yellow lizard monster. Her head consists of a set of sharp-pointed head crests, a pair of round glasses that does not cover her eyelashes, beady black eyes, and a pair of protruding square buck teeth that is constantly visible. Depending on the direction she is facing, it is depicted as as a set of two or four teeth. Alphys has clawed hands, wears a long-sleeved, large white lab coat with her three-toed feet being visible, and her tail jutting out.

Alphys is a shy introvert who is passionate in her work and interests. She has low self-esteem, makes self-deprecating comments, and devalues her skills at times. True to her occupation as a scientist, Alphys is intelligent, analytical, and observant. She occasionally theorizes on matters, and can create thorough plans from those theories. Alphys can create inventions that use both metal and magic, such as a "magical spear repair kit".She is adept in programming, robotics, and mechanical engineering.

Undyne is a piscine, anthropomorphic monster. She has red and blue fins on the sides of her head, blue scales, a long red ponytail and a pair of sharp, yellow, protruding teeth. She wears a red eyeshadow and has an eyepatch over her left eye. She also wears a black tank top and blue jeans, but debuts in armor varying in light and dark shades of gray. Her eyes have black vertical pupils and yellow sclera. Undyne has no nose.

Undyne is hot-blooded and passionate about everything that she does. She acts quickly on her ideas and is steadfast in her beliefs. She also makes an attempt to be fair and offers an explanation of how green mode works. Her training with Asgore taught her the value of pacifism. Undyne loves to help others and mentors Shyren and Papyrus in various skills.

Sans is Papyrus' older brother.

Sans is lazy and relatively laid-back. Sans's dialogue reflects his personality, as he speaks in all lowercase, not even capitalizing names or sentence starters, with a few exceptions, such as the initial beginning of his judgments and other more typical changes to his style of speaking for the sake of emphasis. His laziness is a combination of fatalism and apathy due to being self-aware and knowing of timeline resets. Conversely, he suggests that this knowledge could be "a poor excuse for being lazy."

Sans appears as a relatively short and paunchy skeleton, with mitten-like hands. He has white dots for pupils in his black eye sockets that disappear when he is serious or angered. When Sans uses telekinesis, his left eye flashes light blue and yellow, the colors for patience and justice, and his right pupil vanishes. No matter the mood Sans is in, he is always seen with a wide, toothy-grin on his face. His clothes consists of a blue hoodie with a gray hood, a white t-shirt underneath, black shorts with white stripes on the sides, and a pair of slippers.

Papyrus is Sans' younger brother.

Papyrus is flamboyant and brash, which is reflected by him speaking exclusively in capital letters. He presents himself as confident and charismatic, and seems to be egotistical, referring to himself as "THE GREAT PAPYRUS". However, Papyrus is also hard-working and kind at heart, remaining considerate and forgiving.

Papyrus appears as a tall skeleton, with a skull more vertical and geometric than his brother's skull. Being skeletal, many of his expressions incorporate a toothy grin. His eyes resemble vertical slits; his skeletal pseudo-brows form most of his expressions, as well as the corners of his mouth. He has eyeballs which show at times when he is experiencing strong emotions. Papyrus is relatively taller and slightly slimmer than his brother.

Toriel is the former queen of monsters, the ex-wife of Asgore, the mother of Asriel, and the adoptive mother of the fallen human.

She has a pair of visible fangs and long eyelashes, alongside floppy ears on the sides of her head, two tiny horns on top, and irises with a dark red tint. Her body is anthropomorphic, with paws at the end of her limbs. She wears a long purple robe with white sleeves and the Delta Rune on the chest. On occasion, Toriel can be seen with reading glasses.

Toriel is kind and acts as a protective mother figure for the protagonist. She is sincere in expressing her love through words and actions, as evidenced by her former marriage to Asgore

After the Humans defeated the Monsters in The War, the losing faction was banished into the Underground. A Barrier was erected to prevent the insiders from leaving, though outsiders could still freely enter. Wary of humans, monsters retreated into the Ruins and adapted Home as their first capital,living normal lives in the Underground from then on. Additionally, the Ruins was structured to contain diversions in the form of puzzles.

Eventually, no longer fearing humans, monsters ventured outside of the Ruins, populated the rest of the Underground, and made New Home their new capital.

The Ruins: The starting area, an ancient, purple zone that serves as a tutorial guided by Toriel. Snowdin: A frigid, forested region inhabited by many of the monsters, including the skeleton brothers Sans and Papyrus. Waterfall: A humid, cavernous area filled with water, magical mushrooms, and bioluminescent landscapes. Hotland: A volcanic, technological zone where the True Lab and the domain of scientist Alphys are located. The Capital: Home to Asgore's Castle, guarded by the Royal Guard, where the King awaits.

The world of Undertale, known as the Underground, is a vast, magical subterranean region located in Mount Ebott. Separated from the surface by a barrier, it is home to banished monsters and is divided into five main areas: The Ruins, Snowdin, Cascade, Warm Land, and the Capital.