O ya I thought about that... It would be a new pokemon in the humanshape breeding group something like this:
Classification- Baby Pokemon (caught in wild only way to obtain this pokemon species, also it is a baby pokemon)
Lv. 18 --> Classification: Child Pokemon (Main stat: attack n defense)
Lv. 40 --> Classification: Adult Pokemon (Main stat: Attack n Defense: Base stats: Attack: 150 Defense: 150)
Lv. 80 --> Classification: Senior Pokemon (Main Stats: Sp Attk, Sp Def, and HP. Base Sats: Sp Attk: 180 Sp Def: 180 Hp: 300)