See caption
A zitiron as represented in an illuminated manuscript of Jacob van Maerlant’s poem “Der Naturen Bloeme”, c. 1350
Wikimedia Commons

A zitiron, or sea knight, is a mythological creature with an upper body in the form of an armed knight, fused with the tail of a fish.[1] The sea bishop and the sea monk are similar creatures that appear in Caspar Schott’s Physica Curia (1662).[2]

It was once believed that everything that exists on earth must have its equivalent in the sea.[1]