Ooze, Ink Guardian

A spill of ink slowly grows in size, corroding intruders without harming the nearby texts.

Large ooze, unaligned

Armor Class 8
Hit Points 102 (12d10 + 36)
Speed 20 ft.

16 (+3) 7 (-2) 16 (+3) 6 (-2) 6 (-2) 1 (-5)

Damage Resistances fire, slashing, thunder
Damage Immunities acid
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, prone
Senses blindsight 60 ft. (blind beyond this radius), passive Perception 8
Challenge 4 (1,100 XP)

Special Traits

  • Amorphous. The ink guardian can move through a space as narrow as 1 inch wide without squeezing.
  • Bottled Rejuvenation. When activated, the creature launches from its bottle, landing within 20 feet of the bottle. It starts as Tiny, and at the start of each of its turns, it increases in size by one step to a maximum of Large. When the ink guardian is defeated, the bottle becomes inactive for 3d8 hours. After that time, the ink guardian regains all its hp and is active again. The bottle has AC of 20, 10 hp, and is immune to damage that isn’t bludgeoning. If the bottle is destroyed, the ink guardian dies and can’t rejuvenate.
  • Ooze Nature. An ink guardian doesn’t require sleep.
  • Selectively Caustic. A creature that touches the ink guardian or hits it with a melee attack while within 5 feet of it takes 4 (1d8) acid damage. The ink guardian can eat through flesh quickly, but it doesn’t harm metal, wood, or paper.
  • Volatile. When the ink guardian is subjected to thunder damage, it takes no damage and instead splashes onto creatures within 5 feet of it. Each creature in the area takes 4 (1d8) acid damage. When the ink guardian is reduced to 0 hp, it explodes. Each creature within 15 feet of it must make a DC 13 Dexterity saving throw, taking 9 (2d8) acid damage on a failed save, or half as much damage on a successful one.


  • Multiattack. As a Medium or Large creature, the ink guardian makes two pseudopod attacks.
  • Pseudopod. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) bludgeoning damage plus 7 (2d6) acid damage.


Often left by wizards in libraries or studies, these small bottles produce an ink that can endanger any intruder that might come near. They protect their creators’ residences while posing little risk to the books and manuscripts around them.

Expansive Presence. An ink guardian first appears as a very small blob of ink, but, as it confronts intruders, it grows in size until it is large and imposing.

Projected Protector. The bottles from which these guardians come are often mundane in appearance and seamlessly fit into the environments where they are found.

Dangerous to Intruders. An ink guardian’s ink is corrosive only to flesh, not wood or paper. It is not uncommon for wizards to return to their studies to find no sign of invasion other than the odd staff or pile of clothes lying on the floor.

Section 15: Copyright Notice

Creature Codex. © 2018 Open Design LLC; Authors Wolfgang Baur, Dan Dillon, Richard Green, James Haeck, Chris Harris, Jeremy Hochhalter, James Introcaso, Chris Lockey, Shawn Merwin, and Jon Sawatsky.