NPCs composing that spawngroup :

a_sepulcher_skeleton (50%)

greater_plaguebone (50%)

NPCs spawning around that spawngroup :
(Max range : 100)

charasis_136, range=65 (-72,234,23)

a_bottomless_feaster (100%)

charasis_137, range=85 (-221,246,23)

charasis_138, range=53 (-189,243,22)

charasis_139, range=55 (-188,222,22)

charasis_142, range=65 (-72,234,22)

a_sepulcher_skeleton (100%)

charasis_155, range=24 (-154,224,-139)