NPCs composing that spawngroup :

a_bottomless_devourer (50%)

a_pulsating_bile (50%)

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

charasis_34, range=87 (-409,-405,5)

#The_Crypt_Excavator (50%)
a_helot_spectre (50%)

charasis_36, range=94 (-373,-326,4)

charasis_95, range=36 (-285,-411,4)

charasis_166, range=54 (-267,-412,4)

charasis_167, range=37 (-285,-393,4)

charasis_168, range=55 (-267,-394,4)