Terentatek
Terentatek originally evolved on Korriban, where the power and presence of the dark side gradually distorted their shapes and corrupted their minds. Some sources, however, say that they were first created on Yavin 4 by Exar Kun, as one of his experiments in 3,997 BBY. It is possible that terentateks are highly altered rancors undergoing many experiments. Regardless, terentatek's hide was immune to effects of the Force. They became the most dangerous of the creatures bred by the Sith. They were so powerful and dangerous to the Jedi, that they were often dubbed Jedi Killers.
During an event known as the Great Hunt, numerous Jedi traveled throughout the galaxy to try to exterminate the terentatek. Jedi were often sent in groups of two or three to battle these beasts, and the Jedi of the group had a strong Force bond between them. This was done so that the group could strengthen itself from the dark influence prevalent in the lairs of the terentatek, and as it had to rely on its weaponry skills alone due to the almost complete Force immunity of the terentatek. None of the hunts were successful, however. Even though the Jedi seemingly exterminated a majority of the terentatek each time, the waxing of the dark side would trigger the terentatek to come out of hibernation and repopulate the galaxy. Such events included the rise to power of Revan, Malak, and Emperor Palpatine.
Terentatek were also found on Tatooine, Kashyyyk, Onderon, Tython, and Yavin 4. During the Jedi Civil War, Revan and his companions found and killed a terentatek in Kashyyyk's Shadowlands while searching for the Star Forge. It had been a ceremonial beast used in an old Wookiee ritual. In one such ritual many years ago, Bacca's Ceremonial Blade had broken from its hilt and become embedded in the creature's flesh when a headstrong Wookiee chieftain had attempted to slay it—the blade was recovered by Revan. Revan also single-handedly fought and killed two terentateks in the tomb of Naga Sadow. There was also a terentatek in the Shyrak Caves on Korriban, which turned out to be near the entrance to the tomb of Ludo Kressh.
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