#1 Can be found in the ballpit room with the play place (next to the floating metal box)
#2 Is next to the engineer in the glowing yellow light
#3 Is on top of the toilet in the small apartment (ptsd apartment)
#4 Is at the end of the dark black maze
#5 Is by the ennui box hatch, inside the room with the train (hes saying "VRChat!"
#6 Is by the ring of green couches, under the red light, in the big pink pool room.

Possible Gold headcrab spawns:
#1 Up in the clouds
#2 Waterfall
#3 Sand (tower of power) castle
#4 church of slime
#5 Slime Times
#6 offices