This species of mimic seeks to not only feast on flesh, but magic as well. In this pursuit, they first adopted the guise of a magic wand. However, to be attractive to spellcasters, the arcane mimics had to properly bait the trap. As such, they focused on their caustic nature, developing not only potent acid, but augmenting the power of spells cast through them - especially those of the matching element. They learned that spellcasters were even willing to invest a bit of their lifeforce in pursuit of power, and drain their victims of vitality before eventually striking.

Arcane Mimic

Small monstrosity (shapechanger), neutral

Armor Class 14 (natural armor)

Hit Points 71 (11d6 + 33)

Speed 15ft

Str 12 Dex 17 Con 16 Int 19 Wis 11 Cha 8

Saving Throws Int +6

Skills Arcana +6, Stealth +7

Damage Resistances spell damage

Damage Immunities acid

Condition Immunities prone

Sensesdarkvision 60 ft., passive Perception 10

Languages -

Challenge 4 (1,100 XP)

Shapechanger.

The mimic can use its action to polymorph into a magic wand or back into its true, amorphous form. Its statistics are the same in each form. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.

Adhesive (Object Form Only).

The mimic adheres to anything that touches it. A Large or smaller creature adhered to the mimic is also grappled by it (escape DC 13). Ability checks made to escape this grapple have disadvantage. The mimic can activate or deactivate this ability as a bonus action.

Fiendish Focus (Object Form Only).

The mimic counts as an arcane focus. Any creature using the arcane mimic as an arcane focus may add +2 to the DC of any spell they cast by expending a Hit Die. Any time a creature using the arcane mimic as an arcane focus casts a spell that deals acid damage they may also expend a Hit Die to reroll a damage die.

False Appearance (Object Form Only).

While the mimic remains motionless, it is indistinguishable from an ordinary magic wand.

Grappler.

The mimic has advantage on attack rolls against any creature grappled by it.

Spell Sink.

Whenever the arcane mimic would take spell damage, it instead heals a number of hit points equal to the spell's level instead.

Actions

Pseudopod.

Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d4 + 3) bludgeoning damage. If the mimic is in object form, the target is subjected to its Adhesive trait.

Bite.

Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 5 (1d4 + 3) piercing damage plus 18 (4d8) acid damage. In addition, if the target is a spell caster, it expends its highest level spell slot