NPCs composing that spawngroup :

an_undead_slave (33%)

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

#Xilniov_1432202, range=50 (-485,1196,134)

Spawner_1432207, range=79 (-451,1113,124)

echo1224136, range=82 (-500,1140,132)

echo1224129, range=56 (-491,1195,134)

echo1224128, range=66 (-477,1242,132)

echo1224000, range=30 (-437,1221,132)