NPCs composing that spawngroup :

a_greater_skeleton (33%)

a_lesser_mummy (33%)

a_necro_apprentice (34%)

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

befallen_76, range=89 (-647,-21,-66)

befallen_77, range=81 (-627,-33,-67)

befallen_85, range=98 (-483,71,-78)

a_greater_skeleton (50%)
ice_boned_skeleton (50%)

befallen_98, range=87 (-586,-60,-39)

befallen_105, range=82 (-552,-54,-39)

a_dread_bone (50%)
a_shadowknight (50%)

befallen_116, range=66 (-540,85,-39)

befallen_117, range=65 (-591,88,-39)

befallen_124, range=17 (-556,18,-38)