Firstly DONT do this in the snow zone because something will certainly attack it and you will freeze without fur and it will rage at you because you are clearly visible. Find one and take out anything hostile in the area including dilophsourus' they will attack it and taiming is reduced. Bring a ghillie suit and a pteranodon to fly on because they are faster and easier to mount and demount. Run behind it then feed it beer don't wait around. Park you pteranodon a it away so it's easier because it might rage at it. Fly in the air and wait until you can feed it again and in that time check the area for anything hostile. GOOD LUCK!
For beginners these things will spot you in a split of a second so don’t even think of going up to it with a stimberry in your hot bar. Instead, get a ghille suit and sneak behind it and feed it a beer! Don’t use stimberries it is pain And time consuming unless you have a bush of stimberries. They eat berries after they are tamed though. Not beer.
To tame this creature you have to passively tame it, the best way of doing this is to put on a full set of ghillie as that supply's stealth, then you Aproach it from behind crouching and Feed it a beer!