Genus Clark Kent slipping unobtrusively into a telephone booth for a quick change? Or Nietzsche's more subtle, idealized ubermensch? Professor Ettinger, the people-freezing advocate (viz., Prospect of Immortality, 1964), considers some of the historical models available -- the Orwellian, Shavian, Wellsian, Nietzschean -- and dismisses them all for want of biotechnical panache. Ettinger's hypothetical superman will be genetically engineered and the possibilities for radical transmography (which comprise the bulk of this amusement) are as quixotic as they are anthropocentric. Super-humanity could have the nose of a bloodhound, the ears of a snake, the eyes of an eagle, and, if you want, skin covered with a special type of hair tougher than armor (""Imagine the chagrin of a lion who tries to take a bite out of this model of man!""). And sexually you could have a ball -- or as many of them as you want; consider superwoman ""riddled with cleverly designed orifices, something like a wriggly Swiss cheese, but shapelier and more fragrant"" while supermate sports an assortment of ""protuberances"" allowing a ""million permutations of The Act, tireless as hydraulic pumps."" Similarly he peeks into the economics and sociology of the superfuture -- you'll be the equivalent of a billionaire since everything from food to cars will be free thanks to a negative income tax (?) and those wonderful engineers who will also turn out ""beasties the size of small insects"" (called tidy bees) specially designed to do all the work. Now the point is that you'll surely want to be around to enjoy supermillenium, right? Right. All right, the way to do it -- and here is where the professor gets pitchman serious -- is through cryonics or, for the sake of technical toniness, low temperature anabiosis. That's right, have yourself frozen. Until the superman era. Now Ettinger's apparently very earnest about this; he blasts away at cryonics' critics (Alan Harrington, Asimov, Russell Kirk) for their lack of vision and laments that body-freezing efforts around the country are lagging. . . . ""Human stupidity is formidable."" Now if you're considering refrigeration in the near future, the appendix -- ""information of a slightly more detailed and technical nature"" -- is a must: there's been some trouble, for instance, with the melting process although ""in at least one of the dog-kidney experiments, in spite of noticeable damage, there was long-term survival of the kidneys."" Ettinger is either a very cool put-on or he's nuts about cold turkey.