Weird Planet #4: Attack of the Evil Elvises (A Stepping Stone Book(TM))

After thier spaceship is taken by the Great Ones, Ploo, Klatu, and Lek return to Las Vegas. There they discover an infestation of Elvis
impersonators, in town for a convention. Klatu, Lek, and Ploo are sure the odd-looking humans are up to no good, and it turns out that they're right . . . for once. These are no ordinary Elvises—they are evil aliens from outer space in disguise with nefarious plans to take over Earth!