Jata was an Osumaran who was a companion of the Twelfth Doctor. After the Doctor rescued him from being stranded on Earth, Jata had several adventures with the Doctor on the voyage to Jata's homeplanet Osumare.
In 1899, he crashed onto Earth in Wyoming and was found by Clint Currie. Deciding to "make the best of [the] barbaric world", Jata helped Currie commit crimes. Jata became the mastermind behind a number of big-time hold-ups and robberies. Because the black star on Jata's forehead was unique on Earth, Jata was put on wanted posters that identified Jata as Currie's horse.
Three months after Jata came to Earth, the Twelfth Doctor found his crashed spaceship. He came to town a town that Currie's gang were committing a robbery in. While Currie's gang were robbing a train, the Doctor came to the tree which Jata was tied to. Jata willingly came with the Doctor and the Doctor left a regular white horse with a black star painted on its forehead in Jata's place. Without the Osumaran to guide him, Currie was caught and arrested by the town's sheriff
The Doctor then offered to take Jata back to Osumare. (COMIC: From the Horse's Mouth) However, they had several detours along the way. Jata and the Doctor stopped a Mkali from turning the students of a 21st century school into mindless zombies, (COMIC: Fear Buds) attended the double-wedding of Syllience and Dorella and Arcanbryte and Bowack on Dacea, (COMIC: Royal Wedding) and helped the Worms of Bode 215 blossom into butterflies. (COMIC: Night of the Worms)