Regular pets eat green items that give you a magic/gold find bonus buff, enabled by endgame collar, tags or perhaps special spells used by pets only(t2 perhaps?).
also eats blue items.
now also loots potions and skulls and chaotic embers and gold.
pet no longer engages in combat.
pet eats elemental embers, blood embers and iron embers, perhaps some different type of buff from that.
a pet spell that enables eating of regular legendarys, non tier drops.
passive defensive aggressive could be remade to toggle various settings, like, dont eat embers, dont eat legendarys, dont eat non legendary regular skulls, etc
intended effect, while you are grinding away farming souls and tier gear, looting becomes a breeze, only interesting stuff remains, tier specific items, vendor boons, and other endgame interesting items.
i have no idea how far this dives beyond the scope of what tl2 lets you do with modding. just some ideas i had. i find the standard pets to be pretty much useless in endgame, and can be more annoying than helpful at times. they take one or 2 hits then run away..., and the damage they deal is abysmal even with the tier collars/tags.