The Zmeu (plural: zmei, feminine: zmeoaică/zmeoaice) is a fantastic creature of Romanian folklore and Romanian mythology. Sometimes compared to other fantastic creatures, such as the balaur or the vârcolac, the zmeu is nevertheless distinct, because it usually has clear anthropomorphic traits: it is humanoid and has legs, arms, the ability to create and use artifacts such as weapons, or the desire to marry young girls. In some stories, Zmeu appears in the sky and spits fire. In other stories, it has a magical precious stone on its head that shines like the sun. It likes beautiful young girls, whom it kidnaps, usually for the purpose of marrying them. It is almost always defeated by a daring prince or knight-errant. Its natural form is that of a dragon or balaur.
Most scholars agree that Zmeu's name and appearance is derived from the Slavic Zmey. However, the linguist Sorin Paliga challenges the notion that the Romanian word Zmeu is of Slavic origin, and hypothesizes that the pan-Slavic forms were an early Slavic loan from the Dacian language. The relation with Romanian zmeură ("raspberry") has been deemed to be possible, but rather unlikely, by Alexandru Ciorănescu.
The word also refers to the kites that children fly, as well as the word for dragon in German, Russian, Bulgarian, Norwegian, Swedish and Scottish English.
The "zmeu" figures prominently in many Romanian folk tales as the manifestation of the destructive forces of greed and selfishness. Often, the zmeu steals something of great value, which only Făt-Frumos (the Romanian "Prince Charming"; literally: "handsome youth") can retrieve through his great, selfless bravery. For example, in the ballad of the knight Greuceanu, the zmeu steals the sun and the moon from the sky, thereby enshrouding all humanity in darkness. In the story of Prâslea the Brave and the Golden Apples, the zmeu robs the king of the precious "golden apples"; a parallel can be drawn to the German fairy tale The Golden Bird, the Russian Tsarevitch Ivan, the Fire Bird and the Gray Wolf, and the Bulgarian The Nine Peahens and the Golden Apples — although in all these other cases, the thief was a bird (nevertheless, in some versions of the Romanian story, the zmeu does transform into a bird to steal the golden apples). Usually, the zmeu resides in the "other world" (celǎlalt tǎrâm) and sometimes Făt-Frumos has to descend into his dark kingdom, implying that the zmeu lives underground.
The zmeu has a plethora of magical, destructive powers at his disposal. He can fly, shapeshift, and has tremendous supernatural strength. Ultimately, the abilities of the zmeu are of no avail, as Făt-Frumos defeats him through martial skill and daring.
Some English translations refer to the "zmeu" as the ogre or giant from western European mythologies. Like the ogre, the zmeu likes to kidnap a maiden to be his wife in his otherworldly realm. After Făt-Frumos slays the zmeu, he takes the maiden as his bride-to-be. Similarly, like the giant in the popular British stories of Jack and the Beanstalk, the zmeu returns home to his fortress from his raids into human lands sensing that a human (Făt-Frumos) is lying in ambush somewhere nearby. A Zmeu is also sometimes pictured as a flame who goes in the room of a young girl or widow and once inside, becomes a man and seduces her.