Book Wyrms are neutral monsters that spawn in the [Defiled Lands]] like animals, and are currently the only non hostile [mob from it.

They drop Raw Book Wyrm and Book Wyrm Scales.

Enchanted Book Recycling

Book Wyrms can be fed Enchanted Books, which they will take time to digest. Once enough books have been fed, they will create a fresh new Enchanted Book.

Each enchantment has a "level value" based on the minimum level required to get it on an Enchanting Table, defined as follow :

Enchantment	I	II	III	IV	V
Aqua Affinity	1
Bane of Arthropods	5	13	21	29	37
Blast Protection	5	13	21	29
Curse of Binding	25
Curse of Vanishing	25
Depth Strider	10	20	30
Efficiency	1	11	21	31	41
Feather Falling	5	11	17	23
Fire Aspect	10	30
Fire Protection	10	18	26	34
Flame	20
Fortune	15	24	33
Frost Walker	10	20
Infinity	20
Knockback	5	25
Looting	15	24	33
Luck of the Sea	15	24	33
Lure	15	24	33
Mending	25
Power	1	11	21	31	41
Projectile Protection	3	9	15	21
Protection	1	12	23	34
Punch	12	32
Respiration	10	20	30
Sharpness	1	12	23	34	45
Silk Touch	15
Smite	5	13	21	29	37
Sweeping Edge	5	14	23
Thorns	10	30	50
Unbreaking	5	13	21
Destructive	1	11	21	31	41
Sharpshooter	1	9	17
Economical	5	13	21	29
Safeguard	1
Blazing	20