Leviathan

Leviathan is a 2009 novel written by Scott Westerfeld and illustrated by Keith Thompson. First of a trilogy set in alternative version of World War I, it has Central Powers (known in-universe as "Clankers") using mechanized war machines opposed by Entente Powers (as "Darwinists") who fabricate living creatures genetically. The central protagonists are Aleksandar, son of Archduke Franz Ferdinand; and Deryn, a Scottish girl with dreams of joining the Royal Naval Air Service with her brother. The sequels are Behemoth and Goliath. The first two chapters of this book were released with Bogus to Bubbly: Insider's Guide to the World of Uglies. The book was named the Best Young Adult Novel by the Aurealis Award in 2009, Locus in 2010, and Mir Fantastiki in 2011.