NPCs composing that spawngroup :

#Gniktar_Grinwit (25%)

a_grimling_mystic (75%)

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

HollowshGremlin1328048, range=70 (3603,1993,164)

HollowshOwls2428048, range=70 (3603,1993,164)

#Skrietat_Chu (35%)
an_owlbear_fleshrender (65%)

HollowshDreadmaw_Wolfkin_24333, range=1 (3533,1997,155)

an_owlbear_bonegrinder (100%)

HollowshWolves1328048, range=70 (3603,1993,164)

a_sonic_devourer (100%)

Hollowsh_WolvesDreadmaw_Wolfki, range=1 (3533,1997,155)

#Dreadmaw_Wolfkin (25%)
a_sonic_guardian (75%)