You can tame onyc on mobile you just need bug repellant and use soothing balm on them (if you have one) then feed it with raw meat and then wait until it's hungry again and then you have a onyc! Up this so new players can see this
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!