NPCs composing that spawngroup :

a_bottomless_devourer (100%)

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

charasis_5, range=131 (-513,-274,4)

hexbone_skeleton (100%)

charasis_34, range=93 (-409,-405,5)

#The_Crypt_Excavator (50%)
a_helot_spectre (50%)

charasis_35, range=112 (-321,-405,5)

a_bottomless_devourer (50%)
a_pulsating_bile (50%)

charasis_36, range=18 (-373,-326,4)

charasis_38, range=15 (-402,-314,4)

charasis_39, range=64 (-387,-250,4)

a_sepulcher_skeleton (50%)
a_sepulcher_skeleton (50%)

charasis_40, range=17 (-375,-301,4)

charasis_41, range=180 (-567,-296,4)

a_bottomless_devourer (50%)
a_helot_skeleton (50%)

charasis_42, range=194 (-553,-212,4)

charasis_93, range=178 (-367,-137,4)

charasis_95, range=140 (-285,-411,4)

charasis_105, range=166 (-440,-156,5)

charasis_107, range=172 (-479,-168,5)

charasis_108, range=176 (-390,-138,4)

charasis_166, range=154 (-267,-412,4)

charasis_167, range=129 (-285,-393,4)

charasis_168, range=144 (-267,-394,4)

charasis_182, range=161 (-267,-206,-158)

charasis_183, range=170 (-239,-230,-158)

a_crypt_spectre_189513, range=152 (-439,-171,5)