It's a ... — 英语阅读题

阅读短文，回答问题。 Look! This is my friend Mike. Mike is on the farm today. He sees many animals. He sees a big animal. It is black and white. It gives us milk（牛奶）. He sees a small animal too. It has long ears. It likes carrots（胡萝卜）. Mike is very happy on the farm. 问题：Mike 看到的那只大的、黑白相间的动物是什么？请用 It's a ... 写出答句。