The crab feeder also known as Craghas Drahar is a Prince Admiral from Myr who serves the Triarchy. He is believed to suffer from greyscale - a usually fatal disease that leaves skin stiff, grey, and like stone to the touch.
The crab feeder is first referred to by Corlys Velaryon, who insists during a small council meeting that he is waging war against his fleet. This is causing disruption to important shipping lanes to Westeros. With the crab feeder charging increasingly high tolls for ships to pass through the lanes he controls, Corlys is becoming agitated - he wants to go to war with Drahar, but Viserys isn’t so sure. As we know, Corlys teams up with Daemon to start the war anyway, against Viserys’ wishes.
