I think it’d be more fun to make the cat, bear, and flight form (and something with the treant form) more customizable as we have with the Moonkin form.
For instance, you could do body shapes, manes, teeth options, eye colors, pelt color, markings, and all sorts of other special unique things to add on - generally the same thing you do when creating a new character - give them an actual option list. I’d love to see personalized players out there.
It could also take inspiration from the dragon mount options in armor other traits.