Feast of All Saints
Today is the Solemnity of All Saints, a celebration honoring all saints (not only those officially recognized via the process of canonization, but all people in Heaven, even those whose names are unknown to us). It is a Holy Day of Obligation for Latin Rite Catholics in the United States (and as far as I know, in most other countries).
An archaeic name for the feast was All Hallowed Souls. Hence, the day before was called “All Hallows Eve”, of which “Halloween” is a contraction that has survived into modernity. Given this, an often overlooked but fitting option for Halloween is to dress as one’s favorite Christian martyr. Plenty of severed body parts, flayings, and embedded axes, swords and arrows to challenge your Halloween makeup skills.
(Saint Peter of Verona, Martyr)