Aker

Aker is the earth god of the horizon, depicted as two lions seated back to back, or as a stretch of land with a human head at each end. The pair face opposite directions: one looks toward the western horizon where the sun sets, the other toward the east where it rises. Each night the sun god enters the earth between them, passing through Aker's body to be reborn at dawn. The two lions are named Sef and Duau, Yesterday and Tomorrow. Aker also guards the gates of the underworld and imprisons the coils of the chaos serpent Apophis, holding the threat of darkness in the depths of the earth.