the upper south cave, the north east cave, the caverns of lost hope, the caverns of lost faith and the tek cave are not on mobile, and they don't spawn at the swamp cave or snow cave. i found them in the north west cave, and besides the terrifying cliffs, it was pretty ok. just take some bug repellent and warm armor. and they just sit in certain spots in clusters. the only other creatures in there are araneos, so with a few bug repellents, it's actually pretty easy, but without them the clusters of bats and spiders can be dangerous. you can avoid the cliffs if you don't care about the artifact, but unfortunately if you do want that, you'll have to brave at least one cliff. the cave entrance is so small that i couldn't get my onyc out, so i had to request it.
I go to center caves, 2 in redwoods and floating island are best. Full ghillie, bug repellant, sacrificial sheep, chainsaw, sleeping bags, preserving salt. Use wyvern wing flap your target to safe area make sure bat is just above character level. Kill that ovis with chainsaw! Place sleeping bag just in case.. Put taming mutton in inventory with half stack of salt. Rest of salt and mutton into wyvern. Ghillie up! Bug spray! Walk slow! Stand under feed, do not move. Stand there for 5 mins(might be shorter but dang its long) it goes faster after that first bite. Keep track of repellent back away slow and reapply if needed! Perfect tame every time!