This is a very lengthy solution, I apologize for any inconvience that this causes anyone.
I suggest going for Graug kills first, they're the giant monsters that have a health bar floating above thier head with what looks like three claw marks.
If you have the ability to ride them, that makes things a lot easier as you can bring one to a unnoccupied area and then kill it, they won't fight back. Watch out for other enemies as they can steal all credit for the kill by getting the last hit..
You should have the tracker snapped while going for these and progress should go up 6-7% for every single kill.
Time of day doesn't matter.
You can fast travel or advnce time between Udun Foothill/Udun Crossing on the first map. Hit
and look around from on top the tower, if you see nothing then FT to the other location, do this back and fourth a couple times and then try to AT at either location. Rinse and reapeat.
You can also try the cave to the west on the second map. Thanks to
Epsilon Theta for this second area.
It's possible to spawn right as one dies in your area, just forget about it and fast travel.
I wrote a solution for finding Caragors for the
Break the shackles challenge which I'll repost here:
First map method.
Fast travel to Durthang Outskirts (lower left of the map) and then turn left and head into the stronghold.
In the main area as many as four Caragors can spawn and then if you crawl through the broken cage door tunnel that leads to the bridge you can possibly get two more (although two only ever spawned for me once, mostly just one or sometimes none at all),Here is a video
Epsilon Theta did for his own Caragoer method in Fern Outskirts:
If you have the dominate/ride ability, they won't fight you back after you ride them and get off.
Something else to try is tame one and then kill a bunch while riding on that ones back, drain it for more arrows and then when you want to reset the area, jump off and kill the one yo uwere riding before fast traveling.
Other methods can be found here:
Here is a great solution from
Wwren417 that he wrote for the
"Let them come!" challenge to find Ghûls:
I just found a fast way to spawn the ghuls in a cave. On the first map go to the forge tower in Udun Crossing. There is a cave to the south that should have a bunch of ghuls in it. Kill them but remember no to kill the ones that are running away, they help bring in reinforcements.
If there are no ghuls in the cave, fast travel back to the tower, advance the time to day and then back to night and keep checking back and you should have it in under 10 minutes.Here is a video
Epsilon Theta did detailing the above:
If you would like to upvote their solutions as a thanks, their respective Ghûl solutions along with others can be found here: