There are lots of options :P We could have it that your guy picks mine out for whatever reason, we could have it that your tribe is in trouble and need help, and you're the first one to find someone compatible, or we could go with my guy finds yours(Animal form) and takes it home, and, yeah, those always go fun :P We could also go with something terrible is coming so your kind all over the area are selecting partners, and this could lead to some fun side characters who've also suddenly got magical pet peoples, or go more epic and make this a "Last chance" type thing. Maybe the beings were wronged somehow long ago and the peoples have forgotten about it, and now you're here to see if any are still worthy do be partners with your race. . .