Ophion

Ophion was a Titan and the husband of Eurynome. 'Snake' (ophis) seems to be the base of his name as well. Perhaps to make him sound more fearsome we could call him 'Serpent'.

Eurynome was said to have had a shrine in Arcadia where she was depicted as a mermaid. This means that there was something of a scaly similarity between husband and wife.