This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Revenant (Medieval folklore)
In folklore, a revenant is an animated corpse that is believed to have been revived from death to haunt the living. The word revenant is derived from the Old French word, revenant, the "returning" (see also the related French verb revenir, meaning "to come back").
A possible precursor of the revenant legend appears in Norse mythology, called the draugr or aptrgangr (literally "again-walker"). Stories involving the draugr often involve confrontations with the creature. The draugr resists intruders to its burial mound and is often immune to conventional weapons, which renders the destruction of its body a dangerous affair to be undertaken by individual heroes.