NPCs composing that spawngroup :

a_bottomless_devourer (50%)

a_pulsating_bile (50%)

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

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

#The_Crypt_Excavator (50%)
a_helot_spectre (50%)

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

charasis_37, range=112 (-387,-314,5)

a_bottomless_devourer (100%)

charasis_38, range=121 (-402,-314,4)

charasis_39, range=168 (-387,-250,4)

a_sepulcher_skeleton (50%)
a_sepulcher_skeleton (50%)

charasis_40, range=117 (-375,-301,4)

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)

charasis_183, range=193 (-239,-230,-158)