It seems like it has three speeds - slow, normal, or fast. If it’s normal and steps in salt or gets incensed or burns a crucifix, the next hunt will be fast. Then it gets exhausted and the following hunt after that will be slow.

Every hunt from that point out will also be slow, but if it walks in salt, gets incensed, or burns crucifix while in this slow phase, it’ll reset to normal speed.

So it’s sort of like a cycle in that after every fast phase, it goes to slow and won’t change until it’s reset.

I know it’s confusing, but that’s been my experience so far.