Their nests can actually be found around the castle that’s in the grasslands. The castle there is also a decent base location with nearby deinonychus eggs to snatch and hatch or use for extraordinary kibble to tame things faster. Deinonychus are also great creatures to have to move around and take no fall damage while your mounted, and they also do a bleed effect with their attacks. I would say this is a useful tame, as they can climb walls (such as cliffs, etc.).