Shaback

Shaback is the Minor God of Fens and Swamps.

Venerated by the natives of the Cursed Swamp, though beyond its borders the name Shaback is more of a curse than it is a God. People in neighbouring lands often mutter the word “Shaback” when they stand in something unpleasant.

Source

 * Warhammer Fantasy RPG 2nd ED -- Tome of Salvation pg. 82