Brass Dragon belongs to the category of small dragons... Strictly speaking, among True Dragons, it is considered a small dragon.
When it comes to this point, one can tell by looking at the body size of the Brass Dragon: its body size in the baby dragon stage is extra small, in the teenage dragon stage it's medium-sized, and upon reaching adulthood, it becomes large-sized.
For comparison, the body size of a baby Red Dragon is already medium-sized— at this point, its overall strength is definitely weaker than a teenage Brass Dragon, just like an adult cat is more formidable than a young tiger, but even so, it is not weak, which is why Leon dares to be adventurous right from birth—the dragon was large-sized during its young dragon stage and owns an extra-large body size during its teenage stage.
The Brass Dragon is undoubtedly an Adult Dragon, but its size is just large-sized; reaching extra-large would require it to be middle-aged, over two hundred years old, which is very far away.
