Sources : Sea-ram

Pliny the Elder [1st century CE] (Natural History, Book 9, 67): The sea-ram goes around like a brigand, and now hides in the shadow of the larger vessels riding at anchor and waits in case somebody may be tempted by the pleasure of a swim, now raises its head out of the water and watches for fishermen's boats, and secretly swimming up to them sinks them. - [Rackham translation]

Aelianus [170-230 CE] (On the Characteristics of Animals, Book 9.49): The Ram-fish also is a creature to be dreaded and is dangerous, even if it emerges at a distance, owing to the upheaval in the sea and the wave which it creates. - [Scholfield translation]

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Fish 7.7): The sea-ram (aries piscis) is a fish of the sea, as Pliny says, and is like robbers hidden in the shadow of the great ships standing in the sea. If the pleasure of swimming invites someone, the sea-ram waits, and raises its head out of the water and watches in secret, until it drowns the swimmers. - [Badke translation/paraphrase]