The body is that of a human. He wears a finely made halfplate and riding boots. His cloak and underclothing are ruined, fouled by dried blood and excrement. He is still wearing a full backpack, which comes off easily enough as Jonas repositions the body.
The backpack contains a mess kit, nearly a week's worth of spoiled rations, a whetstone, 50-foot of silk rope, five vials of a liquid substance, and a tightly rolled bedroll. Jonas thinks the bedroll might weigh a bit more than it should, though it could be just soaked with moisture from this most vile room.