NPCs composing that spawngroup :

a_giant_rat (33%)

a_large_plague_rat (33%)

a_plague_rat (34%)

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

befallen_25, range=75 (-159,47,-5)

a_plague_rat (100%)

befallen_24, range=85 (-192,42,-6)

a_plague_rat (50%)
a_plague_rat (50%)

befallen_20, range=81 (-141,-107,-12)

befallen_18, range=82 (-171,-102,-9)

befallen_7, range=87 (-82,-92,3)

a_skeletal_excavator (50%)
a_skeletal_excavator (50%)

befallen_5, range=87 (-223,-53,-11)

befallen_3, range=75 (-215,-28,-11)

befallen_2, range=65 (-77,-45,3)

a_putrid_skeleton (50%)
a_sturdy_skeleton (50%)

befallen_122, range=77 (-201,22,-12)

Zeek (100%)

befallen_125, range=81 (-77,25,3)