The Yellow God by H. Rider Haggard

The moonlight above vanished. Alan was alone in the depths with this devil, or whatever it might be. He could feel hands and feet gripping and treading on him, but they did not seem to be human, for there were too many of them. Also they were very cold. He gave himself up for dead and thought of Barbara.

Then something flashed into his mind. In his hand he still held the revolver. He pressed it upwards against the thing that was smothering him, and pulled the trigger. Again he pulled it, and again, for it was a self-cocking weapon, and even there deep down in the water he heard the thud of the explosion of the damp-proof copper cartridges. His lungs were bursting, his senses reeled, only enough of them remained to tell him that he was free of that strangling grip and floating upwards. His head rose above the surface, and through the mouth of his mask he drew in the sweet air with quick gasps. Down below him in the clear water he saw the yellow head of Big Bonsa rocking and quivering like a great reflected moon, saw too that it was beginning to rise. Yet he could not swim away from it, the fetish seemed to have hypnotized him. He heard Jeekie calling to him from the shallow water near the further bank, but still he floated there like a log and stared down at Big Bonsa wallowing beneath.