The Coloi, also known as the Coloi Rancor, was a type of mutant Rancor created by the Sith Lord Quorlac Fornayh. Over a thousand years before the Galactic Civil War, Fornayh planned to use the creature to overthrow the Sith Empire of his time. To this end, he began developing the Coloi through the means of Sith alchemy, using a fortress on the planet Yorgraxx. His first step in modifying the rancor was to improve its intelligence. He then gave it lighter bones and large wings, so that it could fly. Afterward, he replaced the skin with black metallic plating that could serve as armor. All the changes that he made were genetic, so that more Coloii could be bred, but by the time Fornayh had perfected the creature, the Sith Lord was close to death, so he placed it in stasis in his fortress. He had planned to teach the creature to use blasters and other weapons, but as he no longer had time to do this, he set up flash-teaching facilities in his fortress, to instruct the Coloi template.
In 32 BBY, during the Trade Federation's occupation of the planet Naboo, a Coloi was transported to the city Theed. During a firefight between some B1-Series battle droids and a group of Gungan and Naboo Security officers, a stray blaster shot struck the creature's cage and allowed it to escape. The Coloi then went on a rampage and caused many credits worth of damage.
During the Galactic Civil War, Fornayh's spirit was re-awakened when a ship crashed on Yorgraxx, and he re-animated his Coloi. However, it was killed by a group of Imperials and Rebel Alliance members who had entered Fornayh's fortress and confronted him.
The Coloi was created by Robert Wiese and first appeared in the 2004 role-playing adventure Shadows in the Force. It later featured in the 2012 video game Kinect Star Wars, as a playable-character in the game's "Rancor Rampage" feature.