I was talking to a friend about Plague Inc. and he was playing

>>54059764
Go read Animorphs or watch Stargate. That should answer your question.

>>54059764
Have you never read or watched anything with this plot? It's such a common story.

It's also my magical realm

>>54059764

Hell, I saw one game where the intelligent race were tiny fleas who lived on domesticated non-intelligent herd herbivores.

So yeah this has been done and is actually quite common.

>>54059764
It'd be particularly interesting if the host species is non-sentient and the parasite is the one that does all the thinking.