Just like vanilla animals, Book Wyrms can be bred together, using Foul Candy. Unlike vanilla animals however, they have several traits that can be improved by breeding individuals together and can be viewed using a Book Wyrm Analyzer.

Digesting Time

The time (in ticks) the Book Wyrm wil take to digest 1 "level value". This cannot go lower than 1.

Enchanting Level

Once the Book Wyrm has fully digested that many "level value", it will consume them to spawn an Enchanted Book with a random enchantment obtained by enchanting it with that many levels. This cannot go lower than 1 or higher than 30.

Golden

Very rarely, Book Wyrms can have a golden hide, which allows them to pick treasure enchantments.

Offsprings from 1 or more golden parent are much more likely to be golden (even more so if both parents are golden), although it is never guaranteed.