What does big blue horse mean?

Big blue horse means blue antelope, which is an extinct antelope.

Blue wildebeest is the earliest large mammal to disappear in Africa. Because it looks like a horse and its color is blue, this animal is also called big blue horse. They are close relatives of red antelope and black antelope, but they are slightly smaller. They lived on the prairie on the southeast coast of South Africa and were more widely distributed during the Ice Age. They may be diners and like to eat high-quality grass.

/kloc-in the 0 th and 7 th centuries, European colonists killed a large number of rare blue wildebeests in order to change their habitats into agricultural land. They became extinct around 1880. At present, only four museums have their specimens, which are in Vienna, Stockholm, Paris and Leiden, and there are some bones and horns in other places. The set specimens are not blue, so it is estimated that their blue color comes from the mixture of black and yellow fur.