This is it, that book that became a sensation because of Tumblr. And that is in fact where I first found out about it too, only to be so intrigued by the hilarious chapter titles (ie, “Ganesh is the Very Definition of an Unplanned Pregnancy”) that I had to read it.
Essentially, Zeus Grants Stupid Wishes is a collection of a few myths from various cultures and religions, but told in a somewhat non-canonical but still reasonably accurate manner. And although it may not be everyone’s cup of tea, I found it to be super humorous. My full review of this “no-bullshit guide to world mythology” can be found here.