NPCs composing that spawngroup :

a_twilight_sea_turtle (25%)

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

twilight1360466, range=70 (780,758,-45)

twilight1360465, range=76 (815,661,-55)

twilight1360452, range=30 (854,702,-36)

twilight1360450, range=84 (892,800,11)

twilight1360396, range=62 (900,702,2)

twilight1360395, range=66 (814,672,-54)

twilight1360338, range=93 (752,742,-55)