NPCs composing that spawngroup :

an_undertaker_skeleton (25%)

a_sepulcher_spirit (25%)

elementalbone_skeleton (25%)

hexbone_skeleton (25%)

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

charasis_12, range=79 (12,-294,22)

elementalbone_skeleton (50%)
hexbone_skeleton (50%)

charasis_22, range=68 (6,-276,23)

charasis_23, range=57 (79,-276,22)

charasis_25, range=53 (85,-183,22)

charasis_26, range=34 (86,-217,23)

charasis_27, range=87 (12,-147,22)

a_pyre_golem (50%)
a_pyre_golem (50%)

charasis_31, range=55 (52,-170,23)

charasis_33, range=82 (-28,-207,22)

charasis_112, range=52 (-1,-224,-194)

a_sepulcher_skeleton (100%)

charasis_173, range=53 (63,-278,-176)

charasis_174, range=53 (45,-279,-194)

greater_war_boned_skeleton (100%)

charasis_175, range=48 (25,-185,-194)

charasis_176, range=86 (-25,-185,-194)

charasis_177, range=20 (31,-225,-194)

a_sepulcher_skeleton (100%)

charasis_209, range=64 (116,-224,23)

a_helot_spectre (100%)