The bloated corpse of a decaying gigantic creature is necromatically enhanced and fused with an undercarriage for use as a grisly and terrifying airship. The methane gas from tissue decay keeps it buoyant in atmosphere, but it can be even more flammable than hydrogen if it escapes...
The adventure can take place in a slightly shifted reality, where everybody has a totem (an animal guardian). The totem should be chosen randomly and not by the player, it is ok if "Gorflin the Large," a gigantic and aggressive barbarian, has a mouse for a totem.
These totems will assist the characters in small way. It is up to the characters to determine how to get the assistance; the animals won't solve mysteries for the characters only supply the clues. The character may even have a dream where his or her totem actually speaks to them and reveals some sort of clue.