Monsterley_32_halloween_181012.zip is a release file of the Minecraft resource pack Monsterley Add-on: Halloween, made for Minecraft 1.13.1, 1.13, 1.13-Snapshot. It was published on October 13, 2018 and is 2.7 MB in size. For the full description, screenshots and every other version, visit the Monsterley Add-on: Halloween resource pack page.
How to install: Put the .zip into .minecraft/resourcepacks (do not extract it) and enable it under Options → Resource Packs.