After defeating all bosses in, The Island, I looked and found two 450(max level, brutal) in ice Mountain, and Griffin Mountain, I tamed both and oh boy sure it was pain, both got a quick nibble in my quetzal that actually did a quarter of my quetzal considering my quetzal had a hundred of thousands of hp, ah well bred both of those two, and kept on breeding it until I got to a point its was actually level 1200, I spent like a whole YEAR breeding these guys, got schools work in my way but I manage to find myself able to spend some time breeding this guys and was absolutely worth it, I literally can one shot any titanosaur, and I used it on a boss and the boss stood no chance but still there was a fear of it halving on hp and you know, well anyways, such a great thing I did, I don't know if you can count that as a lifetime achievement but for me I was happy, now... More journey for me awaits. Hope happy ones.