When taming these dont try to trap them as it typically causes them to never go into shield stance. Fret not i have an easy guide, once you get it into shield stance count how many shots it takes to enrage it (normally 5 with a good pump) shoot your amount of counted shots then back up and it will roar, then run up and feed it your narcotic or more ideally biotoxin then immediately back up a good distance and as soon as it is done with its animation it SHOULD go right back into shield stance allowing you to rinse and repeat this method safely on foot. WORDS OF WARNING kill everything nearby as to not mess with the process, you know you are safe to start shooting when it stands straight then goes into its shield stance, ONLY approach it AFTER it does the correct roar since it has 2 roars, the one you are looking for and a fake/taunting roar which if approached when its doing this second roar will cause it to enrage and and start attacking everything for 30 seconds and will kill you very quickly. IF it does the fake roar simply stand back a good bit and wait for it to finish, after it does it'll do the correct roar and you then run up and feed it like normal. with this method and a little practice you can tame one without ever really getting hit whilst on foot. ALSO the second roar isnt nearly as loud as the first and looks a bit different and the acro will laugh at you (literally) after doing this fake roar if it doesnt get enraged by tricking you. Lastly these things are BEASTS, you and a tribemate can grab 2 bred acros with asc saddles and kill alpha monkey with just those 2 acros, they can also solo the hard ice cave on the island but youll want a good saddle, hope this helps and like so others may see

A bit confusing, but a good way to tell a wild acros damage stat without mods:

Use your own acro. Get into shield stance, and force wild acro into shield stance. Whatever the damage done by the acros BITE in shield stance to your own acro in shield stance is the damage stat. For example, if it does 33 damage per bite, it has 33 points into melee. Nothing game breaking but I thought I’d share

You don't need to target its mouth when feeding narcotics or biotoxin, any part of its body will give you the option to feed.

Literally all you need is a good deinosuchus, 100+ biotoxin, and mutton. Just use the regular attack (NOT THE GIGA BITE EVER) and when it roars dismount and feed it the biotoxin and just repeat, easiest way to tame it in my opinion.

Tested taming extensively.

1. The acro does not seem to care about the damage output you are dealing while you shoot it, it cares how many times you shoot it and with what weapon. Use primitive to reduce the chances of killing it. Shotgun is best.

2. While it is doing the fake roar it will constantly regenerate health to full for the entire duration of the animation, this is a great opportunity to lay into it and force it back into shield mode.

3. If you do not shoot it during the false roar, it will become impervious to damage for about 5-6 seconds, do not waste your ammo during this time.

Biotoxin in your last slot. Goot shooter with good damage and ammo.

Find acro you want to tame. Clear the area of other wilds when its not aggroed shoot it untill it goes into stance/guard this means it walking towards you sideways slowly, a few more shots will make it roar. There are THREE roars only one you can feed on and its the roar where the acro throw it head up and back down qucikly and roars mouth wide open. Run and spawn interact, on playstaion its triangle PC 'E" if successful the acro will shake its head like it had a bad taste in its mouth. I run towards its tail ehich makes the acri turn to find ou giving you time to get some distance. Acro will still be in guard stance shoot it again untill you get a feed roar. Repeat untill it knocks out. BEWARE if you miss a feed it will rage and wont heal and trying ti shoot it back into guard will onky kill it. You need to lure it to a dead dino to eat and onky then can you continue the taming process. The low rumble roar with head low the acro will exit guard stance but you can shoot it back into guard stance after this roar.

Always spam interact when feeding narco/biotoxin as sometimes you can pick up stone or berries instead and miss a feed. Do not miss a feed. If you do give it time to kill somethine or you will kill it.

Just don't let up. After each feeding of narcotic or biotoxin. You can continue pumping damage into it. If the does the fake raor. Continue to shoot it while it does this. By the end of the fake roar it should do a real one. If you miss a feeding it will go into adrenaline stat. At which point it will NOT go to shield stance and you must wait for it to stop glowing red. I don't usually clear out wildlife as i use them to heal the Acro if I do mess up. Good luck and hope you get the best Acro's!

Get a good stego and just fight it, when it roars just jump of toss drugs in its mouth and get back on the stego

For me the most important thing taming these guys has been to have a large, open space. They seem to not enter the taming roar if they have to navigate around anything. Pick an open spot, but also clear trees and other blockers.