Mimic, Variant (5e Race)
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A more intelligent variant of the well-known species of shapeshifting predators commonly found in dungeons and the Underdark.
Ability Score Increase. Your Strength and Constitution scores each increase by 1 and pick one from Wisdom, Intelligence, or Charisma to increase by 1.
Age. Mimics reach what passes for adulthood at around 10, but their maximum age is unknown.
Alignment. Mimics tend toward pragmatic neutrality, but may find purpose and inspiration in whatever cultures or persons they encounter and can be of any alignment.
Size. A mimic's true form is amorphous, but can draw itself up to a height of about 6 feet and draw itself in to a height of about 2 inches. Your size is Medium while not polymorphed. As you age, your unpolymorphed size increases in increments of 150 years, capping off at Gargantuan around 450-500 years of age.* (An important caveat here is to ask your DM if you're wanting to play an older mimic. While they can assume a smaller form for the convenience of traveling, having them be too old can break campaigns if they are being played as PCs)
Speed. Your base walking speed is 25 feet.
Adhesive. Due to the sticky nature of your body, ability checks made to escape your grapple have disadvantage.
Amorphous. Due to the amorphous nature of your true form, you cannot benefit from armor, though you can use a shield. Your Armor Class is equal to 11 + your Constitution modifier and you are immune to the prone condition.
Bite. Your maw is a natural weapon, which you can use to make unarmed strikes. If you hit with it, you deal piercing damage equal to 1d4 + your Strength modifier, instead of the bludgeoning damage normal for an unarmed strike.
Darkvision. You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. You can't discern color in darkness, only shades of gray.
Grappler. You have advantage on grapple checks. Whenever a creature one size larger than you or smaller interacts with you or enters a space within 5 feet of you, while you have shape changed into an object, you can use your reaction to attempt to grapple that creature.
Monstrosity. Your creature type is both humanoid and monstrosity.
Natural Shapechanger. As an action, you can polymorph into an object of your Size or Smaller that you have seen, read, or heard about, or back into your true form. While you remain motionless, as an object you are indistinguishable from an ordinary object. If the object is one that would move, such as a cart or wheelbarrow, you are indistinguishable from an ordinary object so long as you are moving in a way that is natural to that object, elsewise make the appropriate Deception check versus Insight. Your equipment does not change with you, however, it may be contained within you as long as your shape has the dimensions to accommodate it. If you die, you revert to your true form. You retain all of your normal statistics while in this form except for your weight, which changes appropriately to the object you've polymorphed into.
Pseudopod. Pseudopod. Your body can can stretch and contort into all manner of shapes, include offensive ones. With this natural weapon, you can use a weapon appropriate to your class and size or use it to make an unarmed strike. If you hit with it using a weapon, deal the damage appropriate to the weapon. If hit without a weapon, you deal bludgeoning damage equal to 1d4 + your Strength modifier. In addition, whenever you make a successful attack with your Pseudopod natural weapon against a creature one size larger than you or smaller, you can attempt to grapple that creature.
Languages. You can speak, read, and understand Common, Undercommon, and one additional non-secret language