The Halloween Add-on for Dead by Daylight has 4 achievements worth 100 gamerscore.
In public matches, with The Shape, stalk for a total of 100 power tier increase.
In a public match, kill all 4 survivors with the TIER III Evil Within.
In a public match, achieve a merciless victory with The Shape using only its 3 unique perks.
In a public match, escape with Laurie using only her 3 unique perks.