Inspired by videos of chicks growing up, which were in turn influenced by my habit of "Gallus = rooster" jokes.
Galluses begin their lives hatching from their eggs: after a few moments, they are able to move and consume food on their own. In the early years of any Gallus, he develops a woolly cyan coat, which in less than a decade is shed and replaced with feathers. And as he gets older, he learns to fly and develop his signature habit of crowing.