In D&D, metallic dragons (bronze, copper, brass) are in opposition to chromatic dragons (red, blue, green, etc.), chromatic being the typical evil, sometimes cruel and selfish dragons while the metallic dragons are mostly altruistic and righteous creatures
You can mutate it onto cheap evasive creatures to ensure it keeps swinging, while multiple mutations compounds the advantage
This was regularly seen at the multiplayer table despite his 7 mana casting cost, but only 682 decks run it as a card or Commander in the format today according to EDHREC.com
Shout-out to Topiary Panther, which can cycle early to fix your colors, and then return with Kirri if you need a 6/5 trampling Plant, with +2/+0 thanks to Kirris boost
This means that when paired with a significant amount of discard-based cards, this commander is capable of growing into a sizable threat with access to evasion through flying and the stability of lifelink