This is Diablos from Monster Hunter. He is considered to be quite a badass monster but he isn't some Trex predator, he's a territorial herbivore that eats cacti.
I wish there were more monsters like this in MH. Too many "Apex predator carnivore" and not enough monsters like Diablos. More giant badass herbivores please. Besides, it makes no sense that we have all these giant carnivores. That would be hilariously bad for the ecosystem. Oh wait, that's why we hunt them, oh yeah. I guess I'd feel bad beating up too many herbivores. I feel bad enough hunting Kirin.
Anyway triceratops are cool and should be the base for more fictional creatures.
Coincidentally MH features my favorite dragon in fiction, Lao. I love how it's just this force of nature come to wreck the human's mountain stronghold and you need to repel it a few times before you actually slay it. Granted I never got to have the full experience of a party of 4 hunters online using the cannon to shoot it while the others hack away.
Oh man you just reminded me of the giant hermit crab that has a similar style of boss