Chara is an Underswap version of Frisk from the original Undertale series, who also serves as the main protagonist of Underswap. After falling into the Underground, Chara embarks on a journey to return to the Surface. Chara is the last of the eight humans to fall into the Underground after traveling to Mount Ebott.
Chara appearance is similar to their Undertale counterpart, but wears a green and teal shirt, rather that the green and yellow from the original game. Chara otherwise looks the same as Frisk, other than their eyes, which are wide open.
Similar to their gender, Chara's personality is quite unknown, same as Undertale Frisk.
Chara's abilities are the same as UT's Frisk, they have the same SAVE, FIGHT, SOUL and ACTing powers.