Mynocks were parasitical, silicon-based giant bats... in spaaaaaaaaaaaace! They had wings and could fly in planetary atmospheres, but could survive equally well in a vacuum. (And how did they maneuver in space?) Shut up. They fed on electrical energy, usually sunlight, but were attracted to spaceships because of their electrical signals and were often found feeding on the power cables. (Seriously, they just flap their wings in space? It's a vacuum.) Shut up. Pilots and starports considered mynocks parasites and insisted that they be cleaned off a ship's hull before landing, to avoid an infestation. (Did they expel gases to move around? Fart power?) Shut up.
Han Solo and Princess Leia encountered mynocks in the belly of a space slug, which had attached themselves to the hull of the Millennium Falcon. Ugly little bastards. (Yeah, well, at least the belly of the slug had an atmosphere. But hey, shouldn't all the air have been expelled when they flew in?) Shut up, you weird parenthetical person. (Seriously, this whole franchise makes no sense! How come you can hear TIE fighters in space? Why do laser blasts move so slow that people can dodge them?) Shut up!