Harley Quinn is top trending Halloween costume this year

DON'T be surprised if you come across multiple Harley Quinns on Monday night, as the supervillain has emerged as the top trending Halloween costume on Google this year.

Quinn is the Joker's accomplice and lover in the DC Comics universe.

The pair met while working as a psychiatrist at an asylum where the Joker was a patient.

Fittingly, the Joker slips into the second spot on the trending list, followed by "Superhero," pirate and Wonder Woman.

Google even kept track of the top trending Halloween costumes for dogs this year, with spider, Ewok, lion, Chewbacca and pumpkin emerging the most popular.

And when it comes to the most popular Halloween treat, that title is reserved for the iconic candy corn.

And over on YouTube, while bizarre clown sightings had been uploaded as far back as 2014, analysts report seeing a sharp increase in late August and reaching peak October 15, following several clown-related incidents in the news.