The crocodile-headed god associated with the Nile and water was Sobek.
Sobek was one of ancient Egypt’s most distinctive deities, represented either as a Nile crocodile or as a man with a crocodile’s head. Because crocodiles lived in the river, he became closely connected with the Nile’s dangerous power, fertility, and life-giving waters. He was also invoked as a protective deity against the threats posed by crocodiles themselves.
Sobek’s worship was especially important in the Faiyum, where the lake and irrigation landscape supported major cult centers, including Crocodilopolis. He was also honored at Kom Ombo, whose temple was shared with the falcon-headed god Horus. Priests sometimes kept sacred crocodiles, and mummified crocodiles were offered at his temples.
Sobek was more than a water god. Egyptian tradition also linked him with fertility, military strength, royal authority, and healing. In later periods he could be merged with Horus as Sobek-Horus or with the sun god Ra as Sobek-Ra. Hapi, by contrast, personified the Nile inundation itself, but lacked Sobek’s crocodile form.