"Pretty Little Liars" just got a little more awesome... and a whole lot scarier.

Sia's mini-me and tween dance prodigy Maddie Ziegler will appear on an upcoming episode of "Pretty Little Liars" this season. The "Dance Moms" star was on set yesterday (May 11) decked out in a spooky costume during a scene with her superfan Troian Bellisario.

Is it just us or does Ziegler kinda look like a ghost? And is she in Radley? We have so many questions. MTV News can confirm that Maddie's character comes in contact with Spencer in a "really creepy way." Her disturbing performance will air in July.

Of course, Ziegler's creep-tastic episode will also feature a nightmare-inducing dance routine. The tiny dancer gave a special shout-out to choreographer Travis Wall for creating a dance that was "so cool but creepy at the same time." The only thing that would make this news any better is if Bellisario and Ziegler danced together.

The "Pretty Little Liars" star has been a longtime fan of Ziegler's work. Last year, Bellisario raved about Ziegler's memorable performance in Sia's "Chandelier" video, calling it "one of my favorite things in years."

In fact, Bellisario was so excited to meet Ziegler on set, she called it the "number one" reason she even went to work yesterday. "I get to be a creepfest with the insanely talented and awesome @madisonziegler1313," she captioned her haunting insta with Ziegler.

We love when "Pretty Little Liars" embraces its dark side, so we can't wait to see Ziegler's scene come to life -- even if it does haunt our nightmares for all eternity.