If it is normal for birds to be in the air, fish in the water and mammals on land, how should we view the mammal whales in the water or the bat in the air? How about birds that don’t fly but walk on land, birds that dive deep into water to catch fish? What about the fish that flies out of the water to catch low flying birds or those that walk on land when the tide has gone?
In nature it is difficult to find distinctions. It appears mammals are to eat plants but some plants eat mammals. Animals are to eat birds and bird grains but some birds (eagle) eat meat. The strong lion is supposed to kill the buffalo but instances are bound when buffalos kill lions. Every creature has a distinctive colour but some jellyfish are transparent and colourless. Most creatures live within their natural skin but some, like some crabs or the snake, regularly sheds its own. Some sea creatures don’t have shells but kill to own one.
Most animals see because of the reflection of surrounding light but others laminate within their eyes to see. Most creatures fertilize inside the female but most fish do so externally. Most fish give birth through eggs but some give birth to live fish direct. Most mammals give birth alive directly but an Australian mammal gives birth through eggs. Most fishes are cold blooded but there is one that happens to be hot blooded.
Generally, blood is red but the octopus has blue. Almost all animals depend on eyes to see yet some have none, yet they hunt successfully. Impossible seems erased in nature. If you consider that most creatures cannot survive heavy pressure of water above them, yet some creatures live in very deep trenches.
We all need feet to walk or move but the snakes are an exception. It can even run faster than some creatures it hunts.
Most big animals or creatures have bony skeleton to keep their structure stable but t big octopus has no bone and is very powerful. Most carnivores have teeth, but the eagles or vultures that feast on meat have none. Fishes are known to have scales but the pangolin is a mammal that has bony body scales.
The list seems endless and the question remains: What is to be considered normal and what is abnormal? Normalcy therefore is a bias of the individual or group reasoning just like the verdict on what is beautiful is a convenience dictation.
Nature seems to be saying that impossibly as a word should not be taken seriously otherwise everything is possible and normal. So it is possible not to breath oxygen and live, like some marine creatures that synthesize chemicals. It is possible not to eat and live. It is possible for a tree to pick up its roots and move to another location. It is possible to just disappear and reappear at another spot just by the decision to move. It is possible to have animals that can speak. It is possible to have a planet where everything in it is the same one colour. It is possible to have a planet that is not solid or round. It is possible to have humans elsewhere. It is possible to see tomorrow in the reflection of some rivers. It is possible to elongate the human frame. It is possible to have one tree with multiple fruits. It is possible for a lion to give birth to a hen; or a tree to rats. It is possible to have a snake with a human head or an animal with multiple heads. The word 'impossible' is a kind of possibility when nature is having fun with the minds of men. If a heavy plane can fly and a monstrous ship floats, then in truth nothing is impossible because they obey different principles.