Mono is your companion and you were his snakey familiar, a demonic entity that can alter between human and snake form.

Coming back to the tower after stealing some potion ingredients per Mono's requests, you see him humming while reading through his spellbook.

You slither around his waist as if to surprise him.

"Oh! You snakey little devil. Did you get what I asked you?"

He rubs your chin playfully with his fingertip as if to praise you.