Reading through some mobs' canSpawn static methods, we can definitely make a few of these more flexible for datapackers who wish to add these mobs to their own biomes. Some of them need a complete logic overhaul while others like the Penguin would best be expanded into a block tag

changed the giant and penguin to use a block tag in ab13501, will look over spawning logic for other mobs that have strange criteria in the nearby future