If u want a Sabertooth, don't go on mountains, just go to Dead Island. Set up a small base in the small island next to Dead Island(The one where nothing spawns). Craft some bolas. Best to take a flying mount. Then come on ground, agro the saber, Bola it. Now hit it once in its head with a tranq arrow, then wait and then shoot another tranq. On its body. Then shoot another on its hips. Be sure to make intervals of few secs. Once it's knocked, go and try to get some Prime Meat. Wait for the Sabertooth's Hunger bar to get less than 900. Then just shove those prime meat in its inventory. And boom. It gets tamed fast. Because it was hungry, it ate the meat faster.
Easily knocked out when you use a bloa. When stuck shoot in head while you can and itll go down quickly. Tranq darts make the process quicker, but arrows will do the job just fine. They can be picked up and dropped into safe taming cages by argies to make this easy tame all the more easy.