Rusalka (plural Rusalki) in Slavic mythology is ghost female mermaid that dwells at the bottom of river. Rusalki are spirits of young women who died violently before marriage and before their natural time was up.
Thus, they were cursed to live in a lake in the form of a mermaid. There they will sing sweet songs to entrap men into the water and drown them. They would also entice children with singing and then tickle them to death. Rusalka can also live on land, climb trees during the night and sing.
Rusalka have pale, almost translucent skin and no visible pupils, though depending on what versions of the myth you read, they sometimes have green fiery eyes. With green or golden hair, which is always wet, and some believe if her hair ever dries, she will die.
Rusalka can have positive effects as she can confer her unused fertility on fields, helping crops to grow.
Marriage can also alter the Rusalka. She goes from wild and lustful to sweet and demure.
There is also an opera titled Rusalka by Czech composer Antonín Dvořák.
Here is a poem by Alexander Pushkin titled Rusalka (work was unfinished and the title was set after his death)In lakeside leafy groves a friar
Escaped the world; out there he passed
His summer days in constant prayer,
Deep studies and eternal fast.
Already with a humble shovel
The elder dug himself a grave,
And calling saints to bless his hovel,
Death—nothing other—did he crave. So once upon a falling night he
Bowed down beside his drooping shack
And meekly prayed to the Almighty.
The grove was turning slowly black;
Above the lake the mist was lifting;
Through milky clouds across the sky
A ruddy moon was softly drifting,
When water drew the friar’s eye – He looks; his heart is full of trouble,
Of fear he cannot quite explain;
He sees the waves rise more than double
And suddenly grow calm again.
Then, white as first snow of the highlands,
Light-footed as nocturnal shade,
There comes ashore and sits in silence
Upon the bank a naked maid. She looks at him and brushes gently
The hair and water off her arms.
He shakes with fear and looks intently
At her seductive, luscious charms.
With eager hand she waves and beckons,
Nods quickly, smiling from afar,
And shoots within two flashing seconds
Into still water like a star. The glum old man slept not an instant
All night. All day not once he prayed;
Before his eyes still hung and glistened
The wondrous girl’s persistent shade.
The grove puts on the gown of nightfall;
The moon walks on the cloudy floor;
And there’s the maiden—young, delightful,
Reclining on the spellbound shore. She looks at him, her hair she brushes,
Smiles, sends him kisses sweet and wild,
Plays with the waves—caresses, splashes –
Now laughs, now whimpers like a child,
Moans tenderly, calls louder, louder…
“Here, monk, here, monk! To me, to me!”
Then vanishes in limpid water,
And all is silent instantly… On the third day the ardent hermit
Was sitting on the shore, in love,
Awaiting the voluptuous mermaid,
As shade was lying on the grove.
Night ceded to the sun’s emergence;
By then the monk had disappeared.
It’s said a crowd of local urchins
Saw floating there a wet gray beard.