The Platypus is a mosaic life form. In other words, it has characteristics belonging to more than one species.
Although it is a mammal, it lays eggs. It is covered in fur, has milk glands and suckles its young.
Its mouth resembles a bird beak and, again like birds, it has webbed feet.
It has venom and leaves its eggs to hatch in a burrow, like reptiles.
Fossil remains of the creature dating back to the age of the dinosaurs have been found (208-146 million years ago). And it has never changed over the intervening years.
The fact is, however, that the platypus IS A FULLY FORMED AND FLAWLESS LIFE FORM that is still alive today and HAS NEVER CHANGED AT ALL OVER THE LAST 200 MILLION YEARS.