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.
Tweel (A Martian Odyssey)
The creatures are highly active and agile, and usually travel in tremendous, city-block-long leaps through the thin Martian air and also aided by the weak Martian gravity. These leaps end with the long beak buried in the ground, as the secondary function of this beak is to stop the creature. They can leap up the Martian cliffs and across valleys with ease. However, they can also move slowly by walking. Upon seeing Jarvis (the human protagonist), trudge along, Tweel walks beside him.