Actually … Whatever can be imagined is possible. But there are two kinds of imaginations. First is simply imagining a unique unreal object like smiling sun or golden apple. Both these entities are capable to be imagined. And yes .. it is not impossible that any real golden apple or real smiling sun should exist in any unidentified world.
So principle is whatever is not impossible is possible. But it does not mean whatever is not impossible is real.
Only thing real is that real toys of golden mountain and flying horse can be made. Nature does not form new things on the basis of possibility of imagination. Only artificial things are made on the basis of their possibility of imagination.
Second type of imagination is even more wild. It is real Pink Panther world where you can capture sun into your bag and can travel to other galaxies in few seconds. These things are NOT possible in reality even in the form of toys but do are possible in the form of animation series. Even mathematics also can represent those animations. But these things cannot be real in any parallel world.