Option to assign pet types (melee/ranged/support) regardless of species
It's unfortunate when your favourite pet is a bit useless for your playstyle/build. They're supposed to be your companion that explore the world together, so why not have the option to customise them as well? Plus, it feels like a natural progression when the pet you've been with for a while adapts to your playstyle.
This is definitely something the player should have to work for though.
* Players should only be able to use skill tree of pets they've discovered & hatched.
* There should be a large cost to assign a skill tree of one type to your current pet (i.e. Pet level must be at max first, and assigning a new skill tree will reset it to 1. It may also require an item that's costly to craft.)