An
alien species on Star Trek: Enterprise. Most of the 3rd season dealt with Enterprise's mission to stop the Xindi from launching a superweapon and destroying
Earth.
The Xindi are actually comprised of
5 sub-species: Primates, arboreals, aquatics, insectoids and reptilians. There was once a sixth species, the Avians, but they went extinct when the Xindi homeworld was destroyed in a civil
war.
After being told by the Sphere Builders that
Earth would destroy the Xindi in 400 years, the Xindi decided to launch a pre-emptive strike. They test-fired a powerful weapon on
Earth, killing 7 million people. Fortunatly, a normally antagonistic temporal agent told
Captain Archer the location of the Xindi; a mysterious region of space known as the Delphic Expanse.
Archer and
Co. sent out to stop the Xindi from launching their planet-incinerating superweapon against
Earth. After months of searching, skirmishes and other setbacks, Archer was able to convince the greater number of the Xindi species they had been manipulated into attacking
Earth by the Sphere Builders.
The Sphere Builders were on the verge of taking over the galaxy in the 26th century, but were defeated by the United Federation of Planets (of which
Earth was the founding member). But the Sphere Builders saw this future, as they had technology that allowed them to forsee alternate timelines. So they tried to have the Xindi destroy Earth to change
history in their favour.
The Xindi-Reptilians still attempted to launch the weapon, but were twarted by Archer, with the assistance of the other Xindi species...
