Creatures such as unicorns are from different dimensions and that's why they are able to appear and disappear. In Japan the unicorn is called a Kirin. In China unicorns only appear when a wise rulers is on the throne or else dies. During the Zhou dynasty the qilin (unicorn) was ranked highly among the animals, above the phoenix or fenghuang. In the Qin dynasty the unicorn lost some prestige but still held a high rank. Never in my study of Unicorn history have I discovered them to be docile.
https://www.youtube.com/watch?v=wuSooa0hxqw