Demi Lovato & Billie Eilish Get Spooked at Universal Studios' Horror Nights!

Demi Lovato and Billie Eilish get into the spooky spirit at Halloween Horror Nights!

The “Sorry Not Sorry” crooner and the “bad guy” singer stopped by Universal Studios Hollywood on Sunday (October 27) in Universal City, Calif.

Demi posed with a group of chainsaw-wielding demons, while Billie Eilish let out a scream with a a couple of “bad guys.”

“It’s not Halloween unless you go to @horrornights at Universal!” Demi shared on Instagram. “Thank you #UniversalHHN for the tricks & treats with some of my favorite people 🎃🖤👻 always a blast.”

Singers Jessie J and Trevor Jackson were also in attendance that night.

Get a closer look at all of the photos in our gallery.

The night before, Demi Lovato hosted her fourth annual Halloween party dressed as Pennywise. See the pics!