piss artist

/P IH1 S AA0 R T AH0 S T/
noun
  1. 1

    Someone who is frequently drunk (pissed).

  2. 2

    Someone who claims knowledge or understanding that he does not possess.

  3. 3

    Someone who frequently ridicules others (takes the piss).

Source: https://en.wiktionary.org/wiki/piss%20artist