Q
The Q Continuum is an extradimensional domain in which the immensely powerful race known only as Q exists. Although they possess almost godlike powers, they also exhibit a child-like petulance and sense of playfulness. This makes them a huge nuisance, and sometimes a threat, to the United Federation of Planets, and its starships. The first recorded contact with the Q Continuum was made in 2364, when Q detained the U.S.S. Enterprise-D, and enacting a courtroom drama in which Q accused the ship's crew of being "grievously savage".
Members of the Q Continuum also seem to be able to harness and control vast amount of energies, and even reshape space-time to their own liking. As far as anyone knows or has been able to find out, members of the Q Continuum are practically immortal. Besides this, very little is known of the Q.
Every remember of the Q Continuum is called Q, but especially one (see picture) has been know to cause trouble and mischief to the crews of the starships U.S.S. Enterprise-D and U.S.S. Voyager, as well as the crew of the space station Deep Space Nine.
One example of how dangerous the Q can be was seen in 2365, when Q transported the U.S.S. Enterprise-D some 7,000 light years beyond Federation space to System J-25, where first contact was made with the powerful and extremely dangerous Borg. This lead to the Borg discovery of the Federation, which in turn has caused untold numbers of Federation citizens to be killed and/or assimilated by the Borg.