Bolotnik

The evil spirit is the master of the swamp in East Slavic mythology. The female version is called bolotnitsa. 

Other names: bolotny, bolotny dedko, the fool of the swamp, the swamp devil, the swamp goblin, the king of the swamp, the swamp; as well as antsybal /antsibul /antsibalka /antsibolit / anchibal/ anchibol, zybochnik, kochechny, omutny; belor. balotnik; Ukrainian bolotyanik, antsibol, netecha[, ocheretyanik (from ocheret — "reed"). 

Antsybal — according to one version is a long-standing borrowing from the Baltic languages, comparable to Lit. ančiabalis — "duck swamp"; according to another version, this is a borrowing of the Czech ančibél, which could be the result of contamination of the words antikrist — "antichrist", and d'abel — "devil", and the convergence of the end part with the swamp occurred later; according to the third version, this is the result of the contraction of the expressions antichrist swamp, antip swamp, antiy bolotny through the intermediate antsibolotnik and antsibolot.

In the Russian North, they usually talked about the female spirit of the swamp, its mistress, the mistress of the tundra — the swamp woman, the swamp woman.

Often, the spirit living in the swamp was considered just a kind of water, a goblin or a devil, and the image of a swamp girl was mixed with the images of a leshachiha, a "free old woman", a mermaid, a water woman and a swamp kikimora.

The appearance of the swampman: a dirty, fat, eyeless creature sitting motionless at the bottom of the swamp, similar to a shaggy man with long arms and a tail. Sometimes it is a shaggy man with long arms and a tail.

It was believed that the swampman and the swamp woman lure a person or animal into a quagmire, where he dies.

Any sounds of the swamp were attributed to the swampman: to lure a person, he quacks like a duck, gurgles like a grouse, roars like a cow (the voice of a drink), moans or laughs (the voices of a white partridge and a snipe on the current).

Also, the swamper, in order to lure the traveler, lights lights in the swamp at night and grows flowers with an alluring aroma.