DeGeneres put the photo of the two together on the screen, and started asking the star about how she approached doing both costumes. But before she could even get her question out, one of the host's assistants popped out from the table in a long black wig, terrifying Halsey to her core.
Laughing afterward, Halsey made the point that she was caught off guard by the host asking about Peters. "You distracted me with the boyfriend question, I wasn't ready," she said with a laugh. "I don't know what's scarier, having to talk about my boyfriend on TV or having that happen."
Before receiving her spooky surprise, Halsey made history on Ellen by delivering the first performance using augmented reality on the show. Singing "Graveyard," Halsey sat and danced around an all-white set in what looked like a bedroom, with an empty doorframe. However, as the song continued, the doorway soon transported viewers into a three-dimensional void filled with multi-colored rose petals. As the camera spun around the void, it turned back to Halsey, on the otherside of the doorframe with the show's audience behind her, making it look as though the camera had truly entered another dimension
Check out the full clip of Halsey's appearance and performance on Ellen below: