Bokrug, The Great Water Lizard, is the lake-dwelling god of the semi-amphibian Thuum'ha ("Voiceless Ones") of Ib in the land of Mnar.
The deity sleeps beneath the calm waters of a lake that bordered Ib and the city of Sarnath. When the humans of Sarnath cruelly slaughtered the populace of Ib and stole the god's idol, the great deity stirred. Each year thereafter, strange ripples reportedly disturbed the otherwise placid lake. On the one-thousandth anniversary of Ib's destruction, Bokrug rose up and utterly destroyed the city of Sarnath, so completely that not even ruins remained. Afterwards, the Thuum'ha race recolonized Ib and thenceforth lived undisturbed. Bokrug first appeared in Lovecraft's short story "The Doom That Came to Sarnath" (1920). The being is also part of Lovecraft's Dream Cycle.