From A Wiki of Ice and Fire
Art by Roman Papsuev
|Book(s)|| A Storm of Swords (Mentioned)|
A Dance with Dragons (Mentioned)
The Rat Cook was an infamous member of the Night's Watch. History has forgotten his real name.
According to legend, the man who would later be known as the Rat Cook was a simple cook at the Nightfort. He became infamous when he served an Andal king a pie that was made of bacon and, unknown to the king, the king's son. The cook killed the prince in revenge for a wrong the king supposedly did to him. The king was unaware of this, however, as he ate and praised the taste and asked for a second piece. The gods, angry because the cook had slain a guest beneath his roof, cursed the cook and transformed him into a massive rat who was doomed to be unable to eat anything but his own young.
According to the story, the Rat Cook is an enormous white rat and all the other rats that inhabit the Nightfort are his descendants.
Such is the infamy of the tale that there is a song about the Rat Cook that is still sung in the Seven Kingdoms, despite the fact that this incident was supposed to have happened hundreds of years before Aegon's Landing. The song is used to represent the repercussions to those who violate the sacred laws of hospitality in the Seven Kingdoms, which is known as guest right.