NPCs composing that spawngroup :

an_apparition (20%)

a_phantom (20%)

greater_plaguebone (20%)

greater_spurbone (20%)

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

citymist_35, range=31 (102,-350,3)

a_bewildered_wanderer (50%)
a_haze_golem (50%)

citymist_54, range=11 (133,-353,39)

a_fog_golem (34%)
a_rambling_fanatic (33%)

citymist_62, range=98 (227,-348,-14)

a_shadow (25%)
plaguebone_skeleton (25%)

citymist_83, range=57 (77,-343,256)

greater_war_boned_skeleton (100%)

citymist_85, range=12 (121,-373,256)

citymist_86, range=52 (121,-312,256)

citymist_87, range=22 (136,-342,275)

citymist_88, range=76 (199,-396,275)

citymist_92, range=86 (162,-284,76)

citymist_96, range=71 (79,-314,77)

citymist_116, range=53 (182,-378,65)

citymist_117, range=86 (214,-349,64)

citymist_127, range=96 (219,-328,274)

citymist_128, range=70 (189,-325,274)

citymist_138, range=81 (64,-412,10)