How do man-o-wars move?
Portuguese man o' war
The Atlantic Portuguese man o' war lives at the surface of the ocean. The gas-filled bladder, or pneumatophore, remains at the surface, while the remainder is submerged. As the Portuguese man o' war has no means of propulsion, they move according to the winds, currents, and tides. Although they are most commonly found in the open ocean in tropical and subtropical regions, they have been found as far north as the Bay of Fundy, Cape Breton and the Hebrides.
Boggart (Dungeons &amp; Dragons)
A boggart is an immature form of a will-o'-wisp, that appears as a small humanoid or will-o'-wisp as it desires; the form is unstable and does not last long before it shifts. A boggart must eat meat and drain life force to grow to maturity, so it hunts humans and larger flesh eating creatures. Its touch carries electrical energy and it can discharge a bolt of energy several feet away. A boggart can magically confuse other creatures by yelling, screaming, shouting, whistling, banging, pounding, thumping, or otherwise making noise. A boggart can also become invisible for short periods. Favorite humanoid forms to take include a small halfling, young gnome, a goblin imp, young xvart, or norker neut. As a will-o'-wisp a boggart is smaller and brighter.