Mass Market Paperback
Publisher: Ballantine Books (1 Jan 1982)
Following Lilith: A Snake in the Grass, this is the second volume. Our unnamed central character arrives in a different body, in a different world. Since this is a different instance of the clone, the early parts of his story are the same, slowly diverging under the different conditions encountered (an interesting idea for a series, that).
Cerberus is a much nicer world than Lilith - it's a global ocean, with enormously tall trees poking above that water, on which the people live. But the twist here is that minds can swap bodies - if two people are both asleep, in close vicinity, then they will wake up in each other's body. This provides the nasty back-taste - older people will want to be young again, and this is how they can. Assuming the population keeps growing.
So it's very much Chalker's familiar themes of corporeal mutability (though a little less than in the third novel, by the way). How identity works in a world where biometrics are no more useful than a car key is a bit glossed over - it's mentioned, but I'm not sure EEG machines would be that useful.
The central story is cleverly constructed, and we find out more about the aliens threatening the Confederacy. And so the overall story progresses..