NPCs composing that spawngroup :

a_sepulcher_skeleton (100%)

NPCs spawning around that spawngroup :
(Max range : 200)

charasis_113, range=164 (-55,99,-194)

greater_plaguebone (100%)

charasis_118, range=103 (-12,147,22)

charasis_121, range=97 (12,147,22)

charasis_136, range=97 (-72,234,23)

a_bottomless_feaster (100%)

charasis_140, range=106 (131,228,23)

charasis_141, range=121 (143,275,23)

a_bottomless_feaster (100%)

charasis_142, range=97 (-72,234,22)

a_sepulcher_skeleton (100%)

charasis_144, range=141 (157,189,23)

charasis_145, range=79 (79,184,22)

charasis_146, range=83 (-6,320,22)

charasis_147, range=110 (12,353,22)

charasis_148, range=34 (9,273,21)

a_bile_golem (100%)

charasis_149, range=48 (-20,257,22)

charasis_150, range=135 (157,279,22)

charasis_151, range=78 (61,173,22)

charasis_152, range=38 (60,224,21)

charasis_155, range=180 (-154,224,-139)

charasis_156, range=161 (-136,242,-162)

a_sepulcher_skeleton (50%)
greater_plaguebone (50%)

charasis_157, range=78 (25,165,-194)

a_pyre_golem (50%)
a_pyre_golem (50%)

charasis_158, range=93 (-25,165,-194)

a_pyre_golem (50%)
a_pyre_golem (50%)

charasis_159, range=152 (-2,92,-188)

a_bottomless_gnawer (50%)
greater_war_boned_skeleton (50%)