sunshinedaydream

It's a funny series of fantasy novels set on a flat world that rests on the backs of four enormous elephants that stand on the back of a cosmic turtle. The turtle seems to be headed somewhere. The stories are all over the map. There's lots of magic, bad puns, peculiar characters, and strange technology. Death (personified) is an key character in many of the stories. He's very funny.

Wikipedia on "Discworld"

Yes, I read the Callahan stories long ago and far away when they originally appeared in magazines in the `970s and 80s... Love the puns!