Xu Qing, nicknamed "Mountain Rat" or "Mountain-Boring Rat" (穿山鼠), because he can quickly traverse mountain caves, is a fictional Song dynasty knight-errant from the 19th-century Chinese novels The Seven Heroes and Five Gallants and The Five Younger Gallants. Xu Qing is the third sworn brother of the "Five Rats", whose other members are Lu Fang, Han Zhang, Jiang Ping and Bai Yutang.