Mermaids and mermen have been known since our earliest recorded history. Records indicate that the Babylonians honored a merman called Ea, over 7000 years ago, he was later named Oannes by the Greeks. This god of the sea had the upper body of a man and the lower body of a fish. Legend has it that much like in the 2006 thriller/fantasy film, Lady in the Water, by M. Night Shyamalan, merfolks spoke to humans in their own language, and imparted on them important knowledge.

Merfolks derive their name from the Anglo-Saxon word mer, which means 'sea'.

Merfolks are also known as: Merefolk, Merfish; Merlady; Merman; Merpeople; Muirruhgach; Merrymaids; Merwife; Morgens; Ningyo (Japanese human-headed fish of immortality); Sea Maids; Sea Maiden; Sea People; Sea Queen; Siren; Tritons; Undersea Folk; Underwater Folk; Water Babies; Water Maid; etc.