From publisher blurb:
Does your Fifth Edition game need more monsters? Then look no further! This supplement, Monsters for the Masters: Giant Insects, provides Game Masters with seventeen giant insects to use in their campaigns. Ranging from a Challenge Rating (CR) of 1/8 (the giant leech) to 8 (the giant slug), these monstrous vermin are a fantastic addition to any Fifth Edition Game Master's arsenal of monsters.
This book is part of the Monsters for the Masters series, a set of 5E-compatible bestiary supplements released under the Open Gaming License. Each supplement focuses on a particular type of creatures, such as giant insects, dinosaurs, demons or angels. The discerning Game Master need only pick up the monsters he desires that fit his campaign needs, without having to spend a significant amount of money on a larger tome for only a handful of useful creatures.
This bestiary supplement uses a common OGL monster entry format as its base, with modifications to support the presentation of Fifth Edition monster statistics that are easy to read and easy to use at the table, all while remaining within its Open Gaming Content roots.