《太平广记·卷四百五十七·蛇二》
忽然看见二个黑色的东西，头的样子类似蛇，象条大船那么大，它的身长望去看不到头，不一会，到了船边，都用头绕着船横着推进，快得象风一样。
风静不波，忽见二物黑色，头状类蛇，大如巨船，其长望而不极。须臾，至船所，皆以头绕船横推，其疾如风。
Suddenly, two black things were spotted that looked like snake heads and were as large as a big ship. Their bodies were so long that their ends could not be seen. After a while, they went to the side of the boat and used their heads to push the boat sideways as rapidly as the wind.