Chara is an alcoholic, because of bad memories. Their love interest is Frisk (Charisk is comin'). They also remember some things while they are drunk. They always get depressed when the askers call them a demon, since, on genocide run, they say: 'The demon who comes when you call it's name.'.
They always get nightmares about Genocide, since some say they are on Post-genocide, and some say that they have got half of Frisk's soul. They were banned from MTT resort for a while. The Askers thought Chara was enemies with Sans (since she is the one who killed Sans) but they were corrupted at the time .
Their appearance is mostly the same, with light brown hair, red blushes, and red eyes. Since they are grown up now, they wear different things. They wear a green jacket, black shirt, and a heart locket.
There can be spoilers ( Maybe? ) while reading this, try to go and read ask-drunk-chara on tumblr.
Drunk Chara is set in an uncertain time post pacifist route. It is shown during the events of Undertale that Chara and Frisk were continuously swapping control over a body. Eventually, Frisk gave up half of their SOUL to resurrect Chara. Chara, terrified of their bad memories, became an alcoholic in a desperate attempt to forget. Eventually they stopped drinking due to Frisk being mad at Asriel to what the 'Askers' (The fourth wall is broken.) do when Frisk is gone, or the Wedding of Sans and Toriel.