Freezing

Spawning data tags simply contain a list of Biomes. If you're referring to this list for a Pokemon, please double-check if it has an Anti Condition or Anti Biome. Anti Conditions and Anti Biomes are a way to essentially state: not in this biome/condition, so you'll need to cross-reference them. For instance, if a Pokemon is set to spawn in is_ocean, but has an anti condition of is_cold, it will not spawn in cold oceans.

Our Pokemon spawns are generally based on default Cobblemon configurations with additions to allow the entire dex to spawn in all Minecraft biomes and supported biome mods. Most biome mods are supported such as Terralith, Oh Biomes You'll Go, Incendium, Better Nether, Gardens of the Dead, and The Bumblezone. Other biome mods may also be compatible, provided they label their biomes with data tags.

Freezing Biomes
minecraft:frozen_river	minecraft:jagged_peaks	minecraft:snowy_beach
minecraft:snowy_plains	minecraft:snowy_slopes	minecraft:grove
minecraft:snowy_taiga	minecraft:deep_frozen_ocean	minecraft:frozen_ocean
minecraft:frozen_peaks	minecraft:ice_spikes	terralith:emerald_peaks
terralith:scarlet_mountains	terralith:skylands_winter	terralith:snowy_badlands
terralith:alpha_islands_winter	terralith:alpine_grove	terralith:ice_marsh
terralith:siberian_grove	terralith:snowy_maple_forest	terralith:snowy_shield
terralith:wintry_forest	terralith:wintry_lowlands	terralith:frozen_cliffs
terralith:cave/frostfire_caves	terralith:glacial_chasm	byg:cardinal_tundra
byg:frosted_coniferous_forest	byg:frosted_taiga	byg:shattered_glacier
wythers:crimson_tundra	wythers:frozen_island	wythers:snowy_bog
wythers:snowy_canyon	wythers:snowy_peaks	wythers:snowy_tundra
wythers:deep_snowy_taiga	wythers:huangshan_highlands	wythers:jade_highlands
wythers:snowy_fen	wythers:snowy_thermal_taiga	wythers:deep_icy_ocean
wythers:icy_ocean	wythers:glacial_cliffs	wythers:ice_cap
wythers:icy_crags