 This book from 1964 is the first Keith Laumer I'd ever read, and oh my God, am I sorry that I had never picked up anything by Laumer before. This book is a total riot. Okay, see, there's this badass dude who discovers that Earth has been invaded by aliens that look like giant dog skeletons, but only he can see them. I have to think that Laumer got together with a roomful of 12-year-olds and asked him what they wanted to see in a science fiction book, and he put all their ideas in this one kick-ass book.