In the fourteenth year Chedorlaomer and the kings who were with him came and defeated the Rephaim in Ashteroth-karnaim, the Zuzim in Ham, the Emim in Shaveh-kiriathaim...
Genesis 14:5

The Rephaim, Zuzim, and Emim were giants. Chedorlaomer and his army must have been very capable. In fact, a Jewish tradition says that he was actually Nimrod under another name.