October 27, 2014 11:25 AM EDT

All Hallow’s Eve. The Holy Evening. All Saint’s Eve. No matter what you call it, the holiday’s true origin is still shrouded in mystery. But before you don your velvet wizard’s cap and giant cat paws this Oct. 31, here’s a look at how the Celtic festival Samhain transformed into what we know today as Halloween.

Read next: Elvira, Mistress of the Dark, Is Halloween’s True Queen

Contact us at letters@time.com.

Read More From TIME

Related Stories

EDIT POST