NPCs composing that spawngroup :

lava_duct_crawler (50%)

noxious_spider (50%)

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

soldungb_31, range=64 (-698,-237,-68)

sonic_bat (25%)
sonic_bat (25%)
sonic_bat (25%)
sonic_bat (25%)

soldungb_28, range=88 (-677,-218,-81)

sonic_bat (50%)
sonic_bat (50%)
sonic_bat (50%)
sonic_bat (50%)

soldungb_27, range=191 (-590,-322,-71)

soldungb_26, range=187 (-587,-303,-69)

soldungb_24, range=125 (-656,-305,-66)

soldungb_23, range=166 (-625,-331,-65)

Solusek_kobold (50%)
Solusek_kobold_shaman (50%)

soldungb_22, range=171 (-638,-355,-65)

a_kobold_advisor (100%)

soldungb_21, range=154 (-652,-345,-66)

soldungb_20, range=173 (-595,-286,-69)

Solusek_kobold (100%)

soldungb_16, range=159 (-603,-240,-79)

soldungb_15, range=176 (-595,-179,-90)

soldungb_13, range=120 (-647,-272,-81)

soldungb_7, range=181 (-581,-224,-73)

soldungb_46, range=116 (-714,-131,-92)

soldungb_48, range=126 (-706,-124,-78)

soldungb_50, range=163 (-696,-87,-100)

sonic_bat (50%)
sonic_bat (50%)

soldungb_51, range=89 (-726,-155,-91)

lava_beetle (100%)

soldungb_52, range=109 (-712,-140,-78)

soldungb_53, range=31 (-751,-208,-68)

sonic_bat (33%)
sonic_bat (33%)
sonic_bat (34%)

soldungb_62, range=181 (-940,-279,-83)

lava_duct_crawler (50%)
lava_duct_crawler (50%)

soldungb_65, range=136 (-895,-205,-78)

lava_duct_crawler (50%)
lava_duct_crawler (50%)

soldungb_66, range=175 (-906,-337,-59)

lava_beetle (50%)
lava_beetle (50%)

soldungb_67, range=143 (-884,-313,-57)

lava_beetle (100%)

soldungb_68, range=131 (-877,-173,-79)