Crystal Mimic

The caster creates an exact duplicate of any creature or item they can touch (Huge or smaller). The Crystal Mimic appears like a copy of the target just made of crystal, 1 action later the crystal coalesces to mimic the color and texture of the target creature or item. 

If a creature is the target, the Crystal Mimic has an AR of 11 and 10 HP. It  possess all the same movement ability (walk, dash, fly) of the original but non of it's physical or mental stats. The mimic is basically a puppet under the casters control and takes an action to have it move or act.  It has a Strength of 8 and does not tire. It is immune to charm, paralyze, poison, disease, and non magical fire, lightning, and radiant damage.

If an item is the target, the mimic can perform all of the functions of simple items like doors, chests, chairs, etc. If a weapon is the target the weapon does the same damage as a common version of the weapon.

The true power of this spell is that with a bonus action use the caster can cause the Crystal Mimic to explode. Everything in a 30 foot radius takes 3d8 piercing damage and 2d8 force damage. If the Crystal Mimic is attacked and destroyed it also explodes but the radius is reduced to 10 feet.

Anyone in the radius of effect when the Crystal Mimic explodes can make a Dexterity saving throw vs the casters spell DC to take 1/2 damage on a success, on a fail they take full damage.

The caster is always aware of where the Crystal Mimic is and if it is moving. The mimic stays until detonated by the caster or destroyed. The caster is capable of detonating the mimic as long as they stay with-in 500 feet of it.

The caster can only create one Crystal Mimic regardless of the original targets size or weight.