Chara

Chara Dreemurr is the last human that fell in Underground before the protagonist, adopted after they fell from the surface by Asgore and Toriel. They live in Snowdin with their brother Asriel, and play a supporting role in the story. You encounter them in the beginning of Snowdin. They take the role of Sans.

Appearance
Chara is a human child around the same size as the protagonist, a bit older than Frisk, having the same height as them. They have light brown hair, black eyes and rosey blushing cheeks. They wear an unzipped light lime hoodie over a white t-shirt. They wear black pants, red gloves and boots. When Chara uses magic their eyes become glowing red.

Personality
Contrary to the common depiction of their Undertale counterpart, Chara does not feel any hatred. Actually, they care a lot about monsters in Underground, especially their family, which consider the coolest.

They like to tease Frisk, who calls "pretty mirror" due to their physical resemblance, and Asriel, calling him Rei, saying often that he's cute and that they are cooler than him, even though Chara considers Asriel the coolest monster in the Underground.

Despite their teasing nature, Chara can be easily offended, for example when Frisk says that Asriel is cooler than them. Chara also has a serious side, they are conscious that monsters are delicate and are determined to save them.

Powers and Abilities
Thanks to their life in the Underground, Chara learnt a lot about magic.

They are able to teleport, taking shortcuts just like Sans, and they can materialize knives on will.

As a human, Chara possesses Determination, which raises their abilities, even though they have less Determination than Frisk, and due to this they are aware of the resets.

Frisk
Chara plays a supporting role in Storyshift. They are very happy when they meet Frisk, starting to follow them in their journey to Snowdin, giving them advices and teasing them. Chara refers to them as "pretty Mirror" or "partner".

Asriel
Asriel is Chara's adoptive brother. They love Asriel a lot, caring about him and protecting him when it is needed. They consider him the cutest and coolest monster in the Underground, and they do not want that any harm is done toward him, as shown when they are worried about Frisk's behaviour.

Trivia
Chara is still alive because Asriel be-friended with them, Toriel asked King Sans to not kill them, because Asriel would be lonely again. Chara fell in Underground only with their black shorts and white shirt, their hoodie was made by monsters and probably found at Garbage Dump.