Adult Oblex

Medium ooze, lawful evil

Armor Class 14

Hit Points 75 (10d8 + 30)

Speed 20ft

STR

8 -1

DEX

19 +4

CON

16 +3

INT

19 +4

WIS

12 +1

CHA

15 +2

Saving Throws Int +7, Cha +5

Skills Deception +5, Perception +4, plus one of the following: Arcana +7, History +7, Nature +7, or Religion +7 +2

Condition Immunities blinded, charmed, deafened, exhaustion, prone

Senses Blindsight 60 ft. (Blinded beyond this distance), passive Perception 14

Languages Common plus two more languages

Challenge 5 (1,800 XP)

(Psionics). The oblex casts one of the following spells, requiring no spell components and using Intelligence as the spellcasting ability (spell save DC 15):

3/day: Charm Person (as a 5th-level spell), Detect Thoughts, Hypnotic Pattern

Amorphous. The oblex can move through a space as narrow as 1 inch wide without squeezing.

Aversion to Fire. If the oblex takes fire damage, it has disadvantage on attack rolls and ability checks until the end of its next turn.

Unusual Nature. The oblex doesn't require sleep.

Actions

Multiattack. The oblex makes two pseudopod attacks, and it uses Eat Memories. Pseudopod. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 7 (2d6 + 4) bludgeoning damage plus 7 (2d6) psychic damage.

Eat Memories. The oblex targets one creature it can see within 5 feet of it. The target must succeed on a DC 15 Wisdom saving throw or take 18 (4d8) psychic damage and become memory drained until it finishes a short or long rest or until it benefits from the greater Greater Restoration or Heal spell. Constructs, Oozes, Plants, and Undead succeed on the save automatically.

While memory drained, the target must roll a d4 and subtract the number rolled from its ability checks and attack rolls. Each time the target is memory drained beyond the first, the die size increases by one: the d4 becomes a d6, the d6 becomes a d8, and so on until the die becomes a d20, at which point the target becomes Unconcious for 1 hour. The effect then ends. The oblex learns all the languages a memory-drained target knows and gains all its skill proficiencies.

Bonus Actions

Sulfurous Impersonation. The oblex extrudes a piece of itself that assumes the appearance of one Medium or smaller creature whose memories it has stolen. This simulacrum appears, feels, and sounds exactly like the creature it impersonates, though it smells faintly of sulfur. The oblex can impersonate 1d4 + 1 different creatures, each one tethered to its body by a strand of slime that can extend up to 120 feet away. The simulacrum is an extension of the oblex, meaning that the oblex occupies its space and the simulacrum's space simultaneously. The tether is immune to damage, but it is severed if there is no opening at least 1 inch wide between the oblex and the simulacrum. The simulacrum disappears if the tether is severed.