Lahamu was the first-born daughter of Tiamat and Apsu in Akkadian mythology. With her brother Lahmu she is parent of Anshar and Kishar, who were in turn parents of the first gods. Lahamu is sometimes seen as a serpent, and sometimes as a woman with a red sash and six curls on her head.
She and her brother/husband are never mentioned separately.
In China Mieville's The Scar, it is briefly mentioned that there exists a large and undescribed sea creature called a lahamu.