Bag of Holding..?

A Mimic that acts as a Bag of Holding. 

The Mimic has a primitive sense of self-preservation, like any predatory animal. This mimic decided rather than eating the people, a steady supply of food was the more advantageous thing. So, it became a Bag of Holding. 

While carrying the bag, you are its designated bearer and can command it telepathically or verbaly using simple phrases in Common (e.g., "Release," "Stop eating"). The bag has two distinct "pockets":

• The Maw: The visible opening functions as the mimic's mouth.

• The True Bag: The extradimensional storage space (as a standard bag of holding, up to 500 lbs./64 cu. ft.), accessible only by the bearer without triggering the mimic.

• Every day, this Mimic Bag of Holding eats one supply of Cheese, or other basic foodstuff (carrots, potatoes or any other "raw ingredient" food) from the supplies within the Bag itself. If you do not have such a thing, it begins to eat random items. 
  
  
• Bite Trap. If any creature other than the bearer reaches into the maw, that creature must succeed on a DC 13 Dexterity saving throw or be grappled (escape DC 13) by the bag's pseudopod-like tongue and take 1d4 acid damage at the start of each of its turns while grappled. The bag can have only one creature grappled at a time. As a bonus action, the attuned bearer can command the bag to release its victim, ending the grapple immediately.

• The bag remains still and inanimate unless provoked, perfectly mimicking a mundane bag of holding to the touch and casual inspection (Investigation DC 15 reveals its true nature). It hungers for living flesh and may vocalize impatiently if unfed for extended periods.

 Regular bag of holding info:

• This bag has an interior space considerably larger than its outside dimensions—roughly 2 feet square and 4 feet deep on the inside. The bag can hold up to 500 pounds, not exceeding a volume of 64 cubic feet. The bag weighs 5 pounds, regardless of its contents. Retrieving an item from the bag requires a Utilize action.

• If the bag is overloaded, pierced, or torn, it is destroyed, and its contents are scattered in the Astral Plane. If the bag is turned inside out, its contents spill forth unharmed, but the bag must be put right before it can be used again. The bag holds enough air for 10 minutes of breathing, divided by the number of breathing creatures inside.
• Placing a Bag of Holding inside an extradimensional space created by a Heward’s Handy Haversack, Portable Hole, or similar item instantly destroys both items and opens a gate to the Astral Plane. The gate originates where the one item was placed inside the other. Any creature within a 10-foot-radius Sphere centered on the gate is sucked through it to a random location on the Astral Plane. The gate then closes. The gate is one-way and can’t be reopened.

Notes: Damage: Acid