So here's a tiny diagram of my fursona's ages :3

0 years: Newborn. Looks almost like a baby dragon.

30 years: It's like 10 human years. Pretty annoying.

80 years: It's like 16 human years (demons' years are like Fibonacci series, it stretches along the years). On their teens, demons exaggerate their armor and sharpen their horns in order to look stronger than they really are. The demon side becomes dominant, and Dragmon begins to look evil. Wings are taken because he chose to live with demons.

627 years: It reaches the adulthood. Horns and spikes take a more definite shape, and muscles grow, depending on their genes and training.

1076 years: It's a projected scheme of my fursona's growth. With a lot of training and focus on getting stronger, he may become like this someday.