i think all kinds of pets should have at least afew different colours so that it adds a bit more variety into pets, some pets colours could be avaliable depending on their type (e.g fire type pets can change colour to red, orange,yellow etc)
another idea could be that pets could have overworld abilities when they reach epic, some pets could be used as mounts while still having their pet abilities in battle and the pet areas (e.g pets could be used as mounts but when you run into battle, they change back to normal size so they can help if they have any talents, the pets would also return to normal if they were not being used as a mount) other overworld abilities could help with plants, an imp could play its violin to give plants all their musical needs,a sprite could use its healing magic and stimulate plant growth, and a lightning bat could circle a pest infested plant, zapping all the pests it can find!
also i got one last idea, here should be green wisps that restore energy, but they would not be too common since that would make pet training too easy, id say something like 15% of finding one
