Book Wurm

Skills:
Perception +6, Stealth +6

Damage Resistances:
Poison

Conditions Immunities:
Poisoned

Senses:
Darkvision 30ft, Passive Perception 14

Languages:
Understands one language, but can not speak.

Challenge:
3 (XP: 2500)

Marked For Death:
As long as a creature has at least one Poison Mark, it is poisoned and must make a DC 13 Constitution saving throw each hour, taking (2d6) poison damage on a failed to save, or half as much damage on a successful one. Also on a success, the target loses one Poison Mark. A Poison Mark can be removed by the Protection From Poison Spell or Similar magic. 
A creature with 6 or more Poison Marks falls prone at the end of each of its turns.

Bite:
Melee Weapon Attack: +10 to hit, reach 5ft, one target.
Hit: 6 piercing damage, and the target must make a DC 13 Constitution saving throw, taking (2d6) poison damage on a failed to save, or half as much damage on a successful one. Also on a failure, the target gains one Poison Mark.

Paper Sharper:
As a Bonus Action, the Book Wurm can fold or unfold its body. While the Book Wurm is folded and remains motionless, it is indistinguishable from a usual sheet of paper.

N/A

Paper Cut:
Within a 30 ft range, the Book Wurm will lash out its tail at anyone around. Everyone within 30 ft range must make a DC18 Survival saving throw, taking (2d8) Paper Cut damage if failed to save, or half as much damage on a successful one. Every creature hit by this will need to make a DC15 Medicine saving throw, failing they will take 2 sting damage each turn until they pass the Medicine saving throw and patch the Paper Cut wounds.

N/A