NPCs composing that spawngroup :

an_enthralled_ulthork (100%)

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

sirens_16, range=71 (-227,18,-108)

sirens_20, range=11 (-301,54,-88)

sirens_51, range=72 (-293,121,-121)

sirens_81, range=67 (-238,91,3)

sirens_84, range=95 (-213,-6,-33)

a_coldspine_seahorse (100%)

sirens_93, range=86 (-353,110,-19)

an_enthralled_bulthar (80%)

sirens_a_coldspine_sea_horse14_takp_import_v0, range=72 (-226,18,-108)

a_coldspine_sea_horse (100%)
a_coldspine_sea_horse (100%)

sirens_223843_takp_import_v0, range=68 (-237,91,3)

an_enthralled_molkor (50%)
an_enthralled_ulthork (50%)

sirens_223859_takp_import_v0, range=10 (-300,54,-88)

a_servant_manatee (50%)
a_servant_sea_elephant (50%)