Gub Tengo was a Sullustan male, according to Legends material, and he resided on the world of Darkknell throughout the Republic Dark Age.
While the Sith Lord Chagras was in power, Tengo's occupation was at a bioweapons manufacturing plant, where he was responsible for injecting spores with poison. A vat collapsing resulted in him losing the function of his legs. After Sith Daiman rose to power on Darkknell, Tengo was reassigned to a different role: modifying old documents to align them with the Daimanite alphabet. Around 1032 BBY, Tengo lived with his granddaughter, Tan Tengo, in an apartment located in the city of Xakrea, and he employed the Human Kerra Holt to care for Tan.