Chinch

Nutrient Absorption: When a Chinch is in direct sunlight, it has resistance against bludgeoning, piercing, and slashing damage.

Ground Passage: The Chinch can burrow through non-magical dirt, silt, sand, or similar loose earthen material. The Chinch does not disturb the material it moves through. 

Tainted Blood: The blood of the Chinch is acidic for 5 minuets after the Chinches death unless it is contained and not exposed to air, if contained it is acidic for 1 week. It can be used to make very potent poisons. With a DC 16 Wisdom check, 1 vial of Chinch blood can be made into a poison that deals 3d6 poison damage.

Multiattack: The Chinch makes three attacks, one grapple, one with its mandibles and one with its forearm or it makes one blade attack.

Grapple: The Chinch attempts a grapple against one creature.

Mandibles: Melee Weapon Attack: +5 to hit, range 5 ft, 1 target. Hit: 1d12 + 3 piercing damage, 1d6 poison damage. The targets maximum HP is reduced by half the amount of piercing damage, the Chinch then heals that much. The Chinch gets advantage on this attack if it has its target grappled.

Forearm: Melee Weapon Attack: +5 to hit, range 10 ft, 1 target. Hit: 2d4 + 3 piercing damage.

Blade: Melee Weapon Attack: +5 to hit, range 10 feet, if the chinch has an enemy that is directly behind it, it can make an attack on the target in front of it, and make an attack on the target behind it for free, this secondary target does not take poison damage. Hit: 3d6 + 3 slashing damage and 2d4 poison damage. The target must make a constitution saving throw DC 14 or be poisoned for 1 minuet.