NPCs composing that spawngroup :

Captain_of_the_Guard (10%)

greater_spurbone (33%)

plaguebone_skeleton (57%)

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

citymist_77, range=67 (-175,-350,264)

citymist_79, range=97 (-146,-342,263)

gyrating_goo (50%)
gyrating_goo (50%)

citymist_108, range=52 (-202,-320,76)

citymist_109, range=65 (-231,-289,76)

citymist_136, range=37 (-245,-391,4)

citymist_137, range=85 (-225,-438,5)

citymist_156, range=67 (-188,-395,4)

a_shadow (25%)
greater_spurbone (25%)

citymista_War_Bone_Overlord00035094065, range=33 (-215,-374,20)

a_War_Bone_Overlord (10%)
greater_spurbone (90%)

citymist_spectral_courier0_takp_import_v0, range=84 (-224,-437,4)

citymist_223157_takp_import_v0, range=92 (-150,-341,263)

gyrating_goo (100%)
gyrating_goo (100%)

citymist_222977_takp_import_v0, range=53 (-201,-319,77)

citymist_223450_takp_import_v0, range=95 (-170,-292,76)

citymist_222966_takp_import_v0, range=1 (-241,-353,5)

citymist_222958_takp_import_v0, range=26 (-224,-374,5)