Wynonna Earp is a weird western series of miniseries about Wyatt Earp's great-great-granddaughter, who belongs to a special division of the US Marshalls that deals with paranormal crime. The series has been around at different times since 1996, but in 2016, it was adapted into a show on SyFy.
The show plays with the premise a bit. Whereas the comic travels all over the west and deals with a variety of strangeness, the tv is set in the town of Purgatory, which Wynonna has to protect from the Revenants, the ghosts of the 77 people Wyatt Earp killed with his magic gun, the Peacemaker. The show also gives a partner to Wynonna named Xavier Dolls, and somehow includes Doc Holliday as a character.
2016 also saw the release of a new comic miniseries, and you can easily see they were willing to make changes to better match the show.
One of those changes was the inclusion of Agent Dolls. He first appears in Wynonna Earp #1 (February 2016), only in the comic, Dolls is Earp's superior officer.
Note: Although Wynonna Earp did not premier on SyFy until July 2016, while the 2016 comic series debuted in February, SyFy bought the rights to the series in July 2015 and the show went into production in September 2015 with an automatic 13-episode order.