In keeping with his steady stream of images from the set, filmmaker Bryan Singer has shared a new picture from the Vancouver soundstages of X-Men: Apocalypse teasing the appearance of a mutant we haven’t yet seen in the long-running film franchise. In the caption for the photo of the dimly lit set, Singer says he’s in the midst of shooting Caliban’s place of “business”. Caliban is an albino mutant who first appeared in the comics in 1981 and has the ability to track other mutants.

However, it’s Caliban’s connection to X-Men: Apocalypse villain Apocalypse (played by Oscar Isaac) that probably explains his appearance in the film. In comics lore, Caliban is augmented by Apocalypse to become one of the supervillain’s four horsemen (of the apocalypse fame, obviously), so it’s a safe bet that he’ll play an integral role in the plot. However, since we haven’t yet heard who’s playing the part of Caliban, it may be a relatively minor role in terms of screentime/dialogue.

Singer also recently shared an image of Jennifer Lawrence and Nicholas Hoult reunited on set in what could be their final X-Men film together, as the initial X-Men: First Class castmembers will fulfill their three-picture contracts with Apocalypse.

Check out both photos below, via Singer’s Instagram. The film also stars returning cast members James McAvoy, Michael Fassbender, Rose Byrne, and Lucas Till plus newcomers Sophie Turner as Jean Grey, Alexandra Shipp as Storm, Ben Hardy as Angel, Tye Sheridan as Cyclops, Lana Condor as Jubilee, and Olivia Munn as Psylocke.

Click here to catch up on all of our X-Men: Apocalypse coverage. The film in theaters on May 27, 2016.