In addition to Pitch Black. A blend of sci-fi and horror, Pitch Black was an ensemble piece, but Riddick was the clear standout of the bunch, managing to be both intimidating and extremely charismatic.
Riddick seemed like the lead of a franchise waiting to happen, so it was no real surprise when Vin Diesel returned to star in 2004's Riddick, despite being only a modest success at the box office, at least managed to win some viewers back by finding more of a middle ground between Chronicles of Riddick and Pitch Black's tone.
Diesel has no plans to retire Riddick any time soon, with Riddick 4: Furya still currently in the works, and a TV spinoff called Merc City also previously teased. It's been a few years since there was a concrete update on Merc City, but considering how determined Diesel can be when he wants a project made, it could definitely still happen.
It was in 2015 that Vin Diesel confirmed he and Riddick franchise director David Twohy were developing a spinoff show called Merc City. While they didn't reveal any specific plot details, Merc City, as one might imagine, will center around the various mercenaries and bounty hunters found within the movies. That seems like a natural idea for an offshoot, considering their prominence in every entry so far, although whether any characters from the films would return - like Katee Sackhoff's (Halloween: Resurrection) Dahl - is unclear. Unfortunately, it was back in 2017 Vin Diesel announced on Instagram he'd read and been thrilled by a pilot script for Merc City.
No public updates about the project have been made since, although that doesn't necessarily mean it's dead. It may just have been delayed to line up with whenever Riddick 4 releases. On that front though, it's unclear if the series would have direct ties to Riddick 4, or if Vin Diesel himself would appear on the show in any capacity. Considering how closely involved Diesel has been with keeping the franchise, it's almost impossible to imagine him not deciding to use his own star power as a way to promote Merc City, even if just through a one-episode guest spot.