NPCs composing that spawngroup :

a_coldspine_seahorse (20%)

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

sirens_10, range=185 (-551,-25,-92)

sirens_11, range=183 (-523,7,-110)

sirens_16, range=138 (-555,202,-154)

sirens_19, range=143 (-577,8,-93)

sirens_39, range=190 (-492,194,-155)

sirens_40, range=156 (-513,150,-151)

sirens_41, range=127 (-544,155,-152)

sirens_86, range=65 (-607,147,-203)

sirens_92, range=83 (-624,192,-204)

sirens_94, range=58 (-694,67,-168)

sirens_96, range=28 (-649,98,-191)