Gigantopithecus
During the Early to Mid-Pleistocene of Southern China, the Gigantopithecus existed, which were some of the most terrifying extinct animals to exist in China, Thailand, Indonesia, and Vietnam. Scientists first discovered their teeth, but its other remains weren’t discovered, most probably because they were devoured by porcupines. They’re closely related to orangutans. They’re massive, and it’s suggested they weighed around 200–300 kg (440–660 lb) when alive. Solely because of their aggressive nature and size, these aren’t the type of mammals you’d want to accidentally stumble upon while on a hike in the jungle in Asia (Wikipedia).