Charisk

Charecters
'Charisk' is a non-official ship in Undertale between two charecters:

Chara:a little child that feel a long time in the underground,was a child of the rolyal Dreemurs familly,died because thry wanted to set the monsters free and apears only once in game.This child only apears in Undertale's infamous run:the genocide route,leaving many to belive that there is something off about that smiling child more info

Frisk:the playable main protagonoist in Undertale with a similar fashion sence to Chara,who is famous with their lack of personality in the game.A child that also feel in the underground for unkown reasons,a child that goes on a jorney to the surface and also save the monsters from underground more info

Cannon realationship
The cannon realationship is quite ambiguous in the game,since the only time that Chara and Frisk comunicate is in the genocide route and even then Chara doesn't speak to Frisk but to YOU the player.

Their relation ship seems more like a parnter ship,as Chara describes you as 'a great partner' in the genocide run,when you chose 'erase'

Fannon realation ship
some people possibly ship it because (quote from a reddit user) '' 'Chara/Frisk have the whole soul buddies/connected personalities/dark mirror or general mirror thing going on. They're both tied up with the Player Concept (Chara arguably more) as well and are both shown to be kids (even though one is now dead/possibly simple remnants of a personality/memories) so with all of the above it means there's effectively a heap of common ground between the two, especially for fans of pacifist interpretations of Chara/sympathetic Chara.'''

Others,because,well (another quote from a different reddit user): '' 'Some people think it's a cute ship. Some people probably just think it's better than the other options in terms of shipping.'''

Regardless,the relationship is mostly all sorts of headcannon.Most popular option is Frisk beeing the pasive,cute,kind person and Chara beeing the strong,protective,carring person.Basicly two people from the opposite angle.