I've noticed that with enough space in a pen and ghille you can tame one in captivity easily. Don't need a second one nearby. Just run out of render distance and come back to a calm hyena if you spook it.
Place one stone foundation and place stone doorways on all four corners, place stone hatch and put four stone walls on second layer, get argie pick up hyandon and drop in top, fly away to de-agro and then crouch up and sit under it, tame through hatchframe
Build a 1x1 out of thatch or whatever your heart desires, grab an argy and drop one in it. You can pet it through the wall! BOOM! Done. I used wood foundation and thatch walls that were lying around. Must be walls, so it can't "see" you. Mine had its head sticking through a wall and I got super close and just started petting it like George from of mice and men.
These are impossible to take if your server is too crowded with players. Their behavior causes them to teleport randomly, and their threat detection AI is way too sensitive. Broken on all official servers currently.
If you somehow have access to Scorched Earth items, be sure to make and consume Cactus Broth before taming this animal; Together with a full set of Ghillie Suit and a clear taming area, you can easily pet it without risking an aggro of either flee or attack kinds.
If there is a small Island,then put on it and it will try to swim but gives up and comes back relax easier to tame. Watch out for the tail when petting from behind. Lost so much of the progress of taming, took another 10 mins.