A maverick member of the mysterious and powerful Q continuum, boasting an IQ of 2005 and God-like powers, Q first appeared in the Next Generation pilot episode 'Encounter at Farpoint'.

Q, as played by John DeLancie, went on to become a popular semi-regular character in the series, appearing on the Enterprise to test the resolve of the crew by placing them in situations both whimsical and dangerous. Q introduced Picard and his crew to the Borg, and also to the legend of Robin Hood. And he was responsible for pitting Picard against a deeply unhelpful anti-time phenomenon in the classic farewell episode of the Next Generation, 'All Good Things'.

As much impish troublemaker as obsessive omnipotent, Q has a fondness for Picard which he tries to bury amid their angry moral squabbling. Their exchanges have highlighted the key role Q plays in Star Trek as the resident iconoclast, scoffing at but ultimately being used to validate Gene Roddenberry's super-positive vision of humanity.

Roddenberry named the character of Q after Janet Quarton, an English fan of the series. But many fans believe Roddenberry based Q on Trelane, a character with very similar powers who appeared in the original series episode 'The Squire of Gothos'. Q has appeared in episodes of Deep Space Nine and Voyager, and it has long been rumoured that John DeLancie would reprise the role in one of the Star Trek films, but he has sadly yet to materialise on the big screen.

Key Q Episodes: The Squire of Gothos (The Original Series), Encounter at Farpoint (The Next Generation), Q Who (The Next Generation), Tapestry (The Next Generation), All Good Things (The Next Generation), Q-Less (Deep Space Nine), The Q and the Grey (Voyager).