Not sure that is viable with balancing being as wonky as it already is. As for "juvenile", you can rename your pet if you want. That was the joy of GW1 pets. They grew in size getting bigger as they got stronger. Not this current Pokémon hot swap nonsense. A fully grown rainbow phoenix in GW1 would rival a skyscale for size. I wouldn't so much if names didn't revert to Juvenile everytime it is swapped out.