of Merman
Source: Webster's dictionaryA crew of explorers from Earth visit a Mars inhabited by reptilian mermen, savage dwarf-like beings with long, tentacled arms, bat-men and a race of civilized macrocephalic gnomes. Source: Internet
The ballads are characterised by sexual encounters between everyday people and human(-like) beings referred to in at least some variants as elves (the same characters also appear as mermen, dwarves, and other kinds of supernatural beings). Source: Internet