"Greetings. I am Chara."
– Chara greeting the player at the end of the genocide run or Hardcore Genocide run
Chara is a child in Solartale who was technically the 1st human. They are sometimes called the demon that comes when people call it's name and is the true final boss of an Abandoned Hardcore Genocide Run.
The battle against Chara can only be entered if the Player in a Hardcore Genocide Run attempts to reset in an attempt to escape the game being permanently deleted. If the player resets, Chara will say "So you tried to reset. I don't blame you. But, I cannot allow you to reset just to destroy this world again. If you defeat me, I will let you reset." They then do what the creator of solartale calls a "Sans Ideology" Which is using your strongest attack first. After that, the fight is exactly the same as the Undertale Fan Game "Determination".
Due to the story of Solartale being the same as Undertale, Chara looks the same as their Undertale Counterpart.
Their Personality is the same as it is in Undertale, but at the end of a Hardcore Genocide or Abandoned Hardcore Genocide Route, Chara is shown to deep down be a nice person, Not forcing the player to delete the world if they don't want to, and preventing the player from resetting.