The Knocker is an enemy in the Dawn of Souls and succeeding versions of the original Final Fantasy, meant to reference the Final Fantasy III Goblin recolors. It is found in the deepest levels (B21 onwards) of the Whisperwind Cove.
Knocker is a mythical creature in Welsh, Cornish and Devon folklore. They are the equivalent of Irish leprechauns and English and Scottish brownies. About two feet tall and grizzled, but not misshapen, they live beneath the ground.