Q (Star Trek)
Beginning with the pilot episode "Encounter at Farpoint" of The Next Generation, Q became a recurring character.  Most of his scenes are both dramatic and funny.  He enjoys annoying Jean-Luc Picard, the serious human captain of the Enterprise D. He serves as a major antihero throughout The Next Generation. He is an important part of both the first and last episodes of the show. Q is first presented as a cosmic force judging humanity to see if it is becoming a threat to the universe. However, as the series continues, his role morphs more into one of a teacher to Picard and the human race generally, although he often does this in ways that seem destructive or disruptive or meant for his own fun. Other times, notably during "Deja Q" and Voyager, Q appears to the crew seeking assistance.  For example, one time all the other Q turned Q human as a punishment.