Implementing a Shoulder-Riding Entity type similar to a Parrot

Okay so I haven't seen anything like this on here and I'm not 100% sure how viable it would be (plus it might be too niche for the time it might take but idk) but I love the idea of giving a living entity the option to ride on the player's shoulder similar to a parrot and/or setting a custom x/y offset or mounting position for an entity that rides the player. This could open up some neat pet possibilities like a sloth that rides on the player's back or a bird that rides on the player's head.

Again, not sure if it's possible / too niche to be worth it but I think it'd be handy :)