The animal on the cover of Real World OCaml is the Bactrian camel (Camelus bactrianus). The Bactrian camel, one of two species of camel, is native to Central Asia and has been used domestically in the area for thousands of years. Even though there are over two million domesticated Bactrian camels, only about a thousand are considered wild.
The Bactrian camel is a large animal at 6 to 7.5 feet in height and 7.4 to 11.5 feet in length. An adult will typically weigh between 660 and 2,200 pounds. The Bactrian camel is distinctive for its two large humps on their back, hefty wooly coat, and dark brown color. It is a herbivore that will eat all kinds of vegetation, though they have been known to feed on dead animals.
Humans have domesticated the Bactrian camel for travel purposes because of its great natural resiliency. For example, the Bactrian camel can thrive in habitats of both extreme cold and heat. It can also go without water for months and when water is available it can consume up to 55 litres.
The cover image is from Meyers Kleines Lexicon. The cover fonts are URW Typewriter and Guardian Sans. The text font is Adobe Minion Pro; the heading font is Adobe Myriad Condensed; and the code font is Dalton Maag's Ubuntu Mono.