The Future is Wild is rather famous for their concept of a flying fish, the Flish. Externally these flying fish look fairly accurate (minus the horizontal tail, which is physically), but many of the details on their biology are very inaccurate, as Pavel Volkv pointed out: 
There are two varieities of flish: the oceanic flish and the forest flish (how many species/genera of both groups is unknown). The ones presented look quite unlike each other: the oceanic flish seems a more primitive species, with a long tail and toothed jaws that expand, being retracted under a beak like shealth when not used. In the oceanic flish all the flippers have a fleshy base, the pelvic flippers acting as rudders when the animal swims and probably also as secondary wings when it flies, in a Microraptor like fashion. A seagull sized animal, it spends most of its time on the air, only resting on the water, and it feeds on the crustaceans known as silver swimmers, which took the place of fish. Forest flish seem morphologically more advanced; for instance, they seem to have given up on the jaws, instead relying solely on the beak like shealth to catch prey, and the pelvic fins developed into legs that allow them to hook on trees. The long bony tail disappeared, leaving only the fin behind, and for some reason they lost the fleshy base of the wings, which instead reverted into a more primitive wing fin design; thus, they fly in a butterfly like fashion on the forest. They are eaten by many forest species.