Changing summoned pet models?

is there any way that i can replace the summoned pet graphics in the base game with that of another npc or creature, without making it into a custom campaign? (for example, if i just wanted to replace hellhound with the rift hound model, or a skeleton with default male/female player character models or a slith or something)

:edit:
sorry, forgot to mention that i’ve never really modded anything before, either in this game or any other

Yes but you will probably break MP, so if you enjoy playing MP with randoms… you won’t be able to any more. If you have a group of friends you play with, they will all need this mod.