WoofAPI.java

BiomeModifications.create(Woof.id("wolf_additions")).add(ModificationPhase.REPLACEMENTS, biomeSelectionContext -> true, (biomeSelectionContext, biomeModificationContext) -> {
            // Iterate all wolf variant types.
            for (Map.Entry<RegistryKey<Variant>, Variant> variantRegistryKey : WoofAPI.VARIANT_REGISTRY.getEntrySet()) {
                // Check if variant can spawn in biome.
                if (!variantRegistryKey.getValue().biomePredicate().apply(biomeSelectionContext.getBiomeRegistryEntry()))
                    continue;
                biomeModificationContext.getSpawnSettings().removeSpawnsOfEntityType(EntityType.WOLF);
                biomeModificationContext.getSpawnSettings().addSpawn(SpawnGroup.MISC, new SpawnSettings.SpawnEntry(EntityType.WOLF, 5, 1, 2));
            }
        });