Frozen Zombie

The same shamble as any other zombie, limited to the surface of the Snow biome after dark. It walks at you and takes whatever route the terrain allows, and on an ordinary night a closed door holds it out. A Blood Moon removes that: doors stop mattering and the snow surface fills with them at once. Frostburn does not stick to it either, so a frost weapon loses its burn against the one enemy you would most expect to use it on.

Expert and above give it the armed version that regular zombies also get. It carries a weapon and swings when you close in, which reaches further than a body bump and takes a larger bite. The safe distance is wider than an early game walker suggests, so keep backing off rather than trading hits.

It is the only source of the snow suit it wears, and the hood, coat and pants drop independently, so completing the outfit takes a few nights of patrolling. The protection on it is small enough to ignore. Take it for the look, not as a gear step.