Tulpy is a fantastic choice for nightmare because of her low noise frequency (+ running doesn’t increase noise), and because of her smaller size. Since her size is tiny, there are several hiding spots to avoid detection as long if you’re far away to not alert the apex predator(s).
‘Guy’ is mainly a prey only character, thus not needed to worry about the hunger causing noise and the slight speed penalty from staying hungry. So all in all, it’s a matter of choice between Tulpy and Guy (And I always go with Tulpy because I love her).❤