There were pictures of three or four-headed characters on Derpibooru, usually fusions of existing characters (and not hydras). So it became the inspiration to using Gilda to represent the Vozonid gods: more specifically, as the four-headed god Pjosaroz, symbol of the spacefaring Vozonid Empire.
Left is Kalandil, god of time and longevity, who extends and determines the lengths of one’s life. At the centre is Pjosaroz (“PYOH-sah-ros”), national god of the Vozonid Empire, guardian of the universe, and patron of the emperors. Right is Nimboz, god of decay and endings.
Who knows, with the right offerings, these three gods will bless you and your works in conquering your day? lol