NPCs composing that spawngroup :

a_coldspine_sea_horse (80%)

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

sirens_4, range=90 (-713,-646,-155)

sirens_5, range=92 (-587,-517,-209)

sirens_6, range=90 (-566,-647,-152)

sirens_7, range=2 (-639,-596,-176)

sirens_82, range=91 (-550,-613,-72)

sirens_85, range=89 (-728,-597,-78)

sirens_101, range=77 (-594,-657,-68)

sirens_103, range=74 (-663,-665,-60)

sirens_104, range=75 (-614,-665,-60)

sirens_105, range=54 (-661,-644,-62)

sirens_106, range=54 (-616,-643,-62)

sirens_142, range=75 (-682,-656,-68)