The Wizard of Zao is the kind of garbage that is still unique enough to be considered a work of art in its own right. And while the writing will make you cringe on just about every page, there are moments where Lin Carter shines through with a bit of brilliance, though this is probably by accident as even a broken clock is right twice a day.
It's a pretty mixed bag. None of the ideas seem original and all seem to be borrowed from other great fantasies written before Carter's time. The Wizard of Zao is just Oz backwards, with an added "A", and the green bald wizard is the main character now. He and his companions go on a bunch of adventures which include running through tunnels being chased by goblins, just like in The Hobbit, and all of this childishness is highlighted by Carter's hilarious sexual references when it comes to the girl, whose name is Ooo (the creators of Adventure Time must be into reading the classics!).
The plot in general is so convenient that it's good for a laugh more than anything. Carter also tries way too hard to be seen as a "literary" author in these pages too, going out of his way to inject random philosophical mini-essays which, to be fair, aren't actually all that horrible. But his attempts at literary wordplay, as far as I can remember, were just cringe.
Still, it's a pretty fun read if you're into the cheesy pulp fiction fantasies of the 1900s, and at least Carter wrote with the childish passion of a true nerd. I picked this up at the used bookstore because I wanted something different to put on my shelf next to my Michael Moorcock, Clark Ashton Smith and Fritz Leibers. I would recommend it if you've already read through authors like that.