The swampy region of the Grim North is known as Whitefen.
Home to the Warlock of Whitefen. Fentrolls. Batrachian Frog folk and their king, Ranirex. Giant frogs, killer newts, and frosty salamanders. Worgs. Goblin toad riders. The black dragon, Ennithraz. Bog mummy. Witch lights. The lost ruins of Fenhall Keep. The Temple of the Frog God (can't really have a swamp without one). Wereboar. Fen peasants, untrustworthy. The fenranger. Quicksand. Doppelgänger. Hang man tree. Bats. The Hobfroglin. The Fen Hydra. The Flickering Fortress.
Needs flesh on these bones.