Chalice acquired by defeating Blood-Starved Beast in the Church of the Good Chalice. You must then interact with one of the vacant tombstones on the left (facing the workshop) and perform the chalice ritual.
Layer 1
Undead Giant (blades)
Layer 2
Layer 3
To the left of the ground level entrance of the large open area, next to the Fluorescent Flower.
Wandering Nightmare (under the platform)
As you enter the huge square garden, go slightly left and through the arches under the central platform.