Let me get this straight... you want a brain-eating aberration that can turn you or any of your companions into a mindless thrall in your camp?
I mean... it's not that different from your average cat.
Well... I serve my cat out of my own free will.

I would genuinely hate if this was a thing.
It makes no sense whatsoever.
Yeah, I'd hate it as well.
The owlbear cub at least makes sense, since owlbears can apparently be tamed and trained (at least to a degree).