"Linux for Hank" -- A book about Linux... that you can read to a two year old.

The digital version (in both PDF and CBZ formats -- DRM free, naturally) is available as a perk (one of many) for everyone who subscribes to The Lunduke Journal.

Right here:
https://lunduke.locals.com/post/72622/back-in-2013-i-wrote-a-childrens-book-for-my-daughter-a-book-about-linux-that-i-could-read