As what you thought was your legs and torso your snap together you realize it isn't your legs. First off you can feel too many legs. Second there is too much of mass down there, your new lower half seems huge. Third there is a decided lack of a certain something between the legs. Cautiously you pull back the sheet and see the lower half of a horse. You grab your head and use it to look over your body. Yep, you got yourself attached to a mare's body.
You cautiously get up, careful of the extra mass. You grab your head and look around the room. It is full of animal lower bodies under sheets. You pull some up looking for your lower half, you find that all the bodies appear to be female. At least in your inexpert opinion. You also realize you are moving, without thinking about it, like you were born with the horses lower half.
Then you think to yourself, 'Hey, maybe my head will stick now.' Then you say, "Not something I ever thought I would say." You try to put it back on but it slides off again. You realize that your body parts will only stick to parts that aren't yours. With this knowledge you tuck your head under the crook of your arm and exit into the hall.
On the door where you couldn't have seen from the floor you see a sign, it says, "Animal Lowers, Quadruped" with a female symbol after it.
With the realization that if you get a bad combination you can just go back to the separating machine you decide to explore some more, maybe see if you can get your body back together before you leave.
You decide to ...