Nurgle is the Lord of Decay, one of the four gods of Chaos in Games Workshop's Warhammer and Warhammer 40,000. He is the god of disease, decay and destruction and oldest of the four. He has the most care for his followers (or indeed, anyone infected by one his "gifts"), leading to his other name, Grandfather Nurgle. He is also god of rebirth, as death and decay breeds new life in many cases. His desire to break down and destroy anything he touches has led to a rivalry between him and Tzeentch, who seeks to build, plot and scheme.
A number of Nurgle's followers have turned to him from the agony caused by his diseases, the "gifts" he bestows on humanity and the universe on a daily basis. The greatest and worst of these is Nurgle's Rot, responsible for the creation of the Plaguebearers that make up the brunt of his daemonic forces. He is also responsible for kidnapping the Elven/Eldar goddess Isha, using her to test his newest poxes before he unleashes them on the mortal world. Isha, however, secretly whispers the antidote to mortals after her healing so she can keep the world from succumbing to Chaos.