NPCs composing that spawngroup :

giant_water_moccasin (100%)

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

spawn17228, range=162 (1351,706,-21)

spawn21622, range=88 (1168,539,20)

#Sugal_The_Fist_189210, range=85 (1174,535,20)