Thread Mimic
Tiny monstrosity (shapechanger), neutral
Armor Class 20 (natural armor)
Hit Points 31 (9d4 + 9)
Speed 5 ft., 360 ft. in the Internet
STR DEX CON INT WIS CHA
6 (-2) 20 (+5) 12 (+1) 6 (-2) 15 (+2) 12 (+1)
Skills Stealth +5
Damage Immunities necrotic
Condition Immunities prone
Senses blindsight 60 ft., Passive Perception 11
Languages --
Challenge 2 (450 XP)
Proficiency Bonus +2
Shapechanger. The mimic can use its action to polymorph into a forum thread or back into its true, amorphous form. Its statistics are the same in each form. It reverts to its true form if it dies.
Entangling (Thread Form Only). The mimic entangles anyone who engages it. A Huge or smaller creature entangled with the mimic is also restrained by it (escape DC 15). Ability checks made to escape this grapple (only Intelligence-, Wisdom-, or Charisma-based checks permitted) have disadvantage.
False Appearance (Thread Form Only). While the mimic remains motionless, it is indistinguishable from an ordinary forum thread.
Actions
Pseudopod. Melee Spell Attack: +7 to hit, reach 5 ft., one target currently reading the thread.
Hit: 7 (1d4 + 5) psychic damage. If the mimic is in thread form, the target is subjected to its Entangling trait.
Neurovore. Melee Spell Attack: +7 to hit, reach 5 ft., one target currently reading the thread.
Hit: 7 (1d4 + 5) psychic damage plus 4 (1d8) necrotic damage.