Merman pantheon — father of water elementals
This is the child of Heler and Triolina, and all undines are descended from him. There are several upper echelons of these creatures who cannot be commanded by mere mortal priests or magicians. One of those is Tidal Wave, another is Ship Beater, a third is Island Gulper. One son of Tidal Wave is called Sog, who is famous for his many stations of worship where the ancient Waertagi used to land. Sog is also parent of the three Father Undines who spawned in turn the nine Giant Undines whose clans are the source of the many different elementals of the Neleomi sea and its many rivers.
His portrayals show a wave, sometimes with a face or arms.