Mutant murloc

Though murlocs abound along the rugged coastal regions of Kalimdor, there is a mutant strain of the race that has emerged in months recent to the Third War. Though it is unclear what has caused the creature's strange mutations, many agree that something dark and sinister is awakening deep beneath the raging Maelstrom. The mutant murlocs have been so corrupted that they have been known to turn on their own brethren under duress.

Third War
Murloc Mutants appear in Warcraft III as level 6 units, but rather weak creeps. They are large green murlocs able to cast Cripple. They are slightly stronger as of The Frozen Throne expansion. Also, the bonus orc campaign The Founding of Durotar features some special Murloc Mutants. These are level 9, immense and extremely strong murlocs, expert at spellcasting.

In the RPG
The mutant murloc is a new breed of murloc which has appeared in recent times, originating from an unknown source beneath the Maelstrom. These creatures surpass their brethren in cruelty, hunting humans and others not for sacrifices but for pure joy of torture. Mutant murlocs enjoy blood sport and their victims' agony. Many eat victims over a period of days, careful not to kill them too soon. More prosperous mutant murlocs use healing magic to sustain the entertainment longer. They were said to become increasingly common than their normal counterparts.