A Roc (name unofficial) is an eagle like enemy which is fought in the Rockshard Rampart. It is similar to the Harpy, except that the Roc is stronger and the Harpy is fought in the Sheerdrop Spire. It looks like a mutated eagle with a beastly face above what would look like a normal eagle face. It is a large, strange and deadly bird-creature much like the Roc of myth which was a huge bird with massive talons. They're found on the outside of the tower.
When found in daytime they hold the pillbug servants found in the tower and drop them down to attack you, after that they'll try swooping in with their talons. At night they don't hold the pillbugs but instead just attack.
A good strategy is to keep launching it with the chain and after two or three hits it should be defeated.