NPCs composing that spawngroup :

giant_wooly_spider (100%)

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

permafrost_32, range=195 (993,-70,3)

an_icy_terror (50%)
an_icy_terror (50%)

permafrost_51, range=191 (1024,-2,3)

an_icy_terror (50%)
an_icy_terror (50%)

permafrost_88, range=153 (933,-72,-108)

a_giant_polar_bear (100%)

permafrost_89, range=115 (928,-23,-108)

a_giant_polar_bear (50%)
a_giant_polar_bear (50%)

permafrost_90, range=55 (894,58,-80)

permafrost_93, range=78 (763,69,-38)

an_ice_giant (50%)
an_ice_giant_magus (50%)

permafrost_142, range=192 (680,158,-29)

an_ice_giant (100%)

permafrost_144, range=177 (678,-25,-29)

an_ice_giant (100%)

permafrost_145, range=121 (743,-26,-29)

an_ice_giant_youth (100%)

permafrost_146, range=56 (895,42,-31)

an_ice_giant_magus (100%)

permafrost_147, range=146 (759,172,-29)

an_ice_giant (100%)

permafrost_154, range=117 (953,21,-77)