Hour of the Gremlins

Three novels of fast-moving adventure — and side-splitting humor — in one book: Hour of the Horde by Gordon R. Dickson: Against an approaching merciless alien horde is an outnumbered galaxy-wide legion.
Wolfling by Gordon R. Dickson: Earth was only a primitive outpost, its people dubbed primitive wolflings by the galaxy’s rulers — until Jim Kell was sent to the rulers’ Throne World.
Gremlins, Go Home by Gordon R. Dickson and Ben Bova: Suppose that elves, gremlins, and leprechauns are really aliens marooned on Earth centuries ago. Now they can go home — if they can hijack NASA’s Mars rocket!