‘An obstinacy of buffalo’ is lovely, as you can see them deciding not to move and then staying planted where they stand.
We watched an obstinacy of dog when we were in Italy. He was crossing a busy, blind bend with his so-called master, and then he decided to sit down in the middle of the road and not budge. The owner was yanking his lead and the more he yanked and yelled, the more the dog held his head up in a quietly decisive canine ‘Nope’. The owner had no way to drag, let alone carry him. The traffic was stopped.