In a photo on his Instagram, "X-Men: Apocalypse" director Bryan Singer appears in a tunnel he calls "Caliban's place of 'business,'" hinting at the mutant-locating Morlock's appearance in the film.

Caliban, named after the grotesque character who appears in Shakespeare's "The Tempest," boasts the ability to locate mutants and frequently used his powers for Callisto, the mutant leader of the Morlocks. The Morlocks live underground in a series of tunnels, just like the one pictured in Singer's photo, because of their freakish appearances. Caliban also becomes one of Apocalypse's four Horsemen. No actor has been announced for the role.

"X-Men: Apocalypse" is scheduled to open on May 27, 2016.