This is a real Chinese water deer (Hydropotes inermis) skull! Visually similar to a musk deer, these bizarre cervids are known for their lack of antlers and extremely large canine teeth.
They can be found along the lower area of the Yangtze River, coastal Jiangsu province (Yancheng Coastal Wetlands), and islands of Zhejiang of east-central China, and in Korea, where the demilitarized zone has provided a relatively-safe refuge for their population.
This particular ~6" fanged deer skull was an invasive animal, introduced to the United Kingdom. It can be shipped worldwide.