I wanna say a Wolf so bad, but that would be my nostalgia for Wolfwalkers coming in. I’d go with a Deer because they are normally ignored where I’m at so it would be a peaceful trek to help me explore.
I'd be a dog, whether it's being a stray or a simple housepet would be amazing. I'd go for a stray just because I'd be able to hump and screw anything I wanted with little repercussions. Though now that I think about it, a housepet wouldn't be too bad as long as I'm not neutured/spayed.