The Crab Zine is a huge book all about crabs! This 150+ page PDF includes pieces from 140+ different artists, all centered around some pretty cool crustaceans.
This zine is 100% free using the coupon code 'crablife': https://gum.co/QYpiZ/crablife
The zine raised around $60 and donated it to the Monterey Bay Aquarium! Donations are no longer excepted and people who pay for the zine will be refunded (so please download it for free!).