Linguist

You are gonna need some brains to understand all that jibber-jabber, son!

The ability to understand foreign languages, like Japanese (see Kakuri Island).

Also determines your ability to make .xX~SiCk TaGs~Xx. using cans of spraypaint, which add a temporary chill bonus to rooms. Great for de-stressing on the go or telling somebody that you don't think highly of their mother.

Linguist is currently one of the most powerful skills and teaching it to other players should be done with great care if they might be prone to engaging in PVP activities against you at some later point.