From A Wiki of Ice and Fire
The crannogmen are so called for their habit of living in small villages formed of reeds and thatch that sit atop floating islands in the mire (crannogs). They are a poor people and seldom leave their lands, subsisting on fishing and frogging.
They are talented hunters and warriors and despite their short stature and somewhat primitive lifestyle, the crannogmen have proven a notoriously difficult people to conquer. They use nets, bronze knives, frog spears, and round leather shields. They fight with poison, guerrilla tactics, and a mastery of their difficult terrain. According to those who have fought them, their houses, even their castles, move. They are disparaged as "frog-eaters, swamp-dwellers, mud-men and bog devils" by most other people of the Seven Kingdoms, and are looked down upon for their tactics, which are viewed as cowardly.
The histories say that the crannogmen grew close to the children of the forest in the days when the greenseers tried to bring the hammer of the waters down upon the Neck. They swore oaths of fealty to the Starks thousands of years ago, when the King in the North defeated the Marsh King and took his daughter as wife. They are ruled by House Reed from Greywater Watch. Other families of crannogmen are House Fenn, Peat, Boggs, Cray, Quagg, Greengood and Blackmyre.
|“||I've sent word to Howland Reed, Father's old friend at Greywater Watch. If the Lannisters come up the Neck, the crannogmen will bleed them every step of the way.||”|
|“||Mudmen are sneaks, they won't fight like decent folks, they skulk and use poison arrows. You never see them, but they see you. Those who go into the bogs after them get lost and never come out. Their houses move, even the castles like Greywater Watch.||”|