Green Slime

An ordinary slime, the weakest of its kind. Becomes more difficult to defeat the stronger you get.
Stats:
AC: 15 (natural armour) HP: 53 (4d20 + 2d10) Speed: 20 ft
Str: 10 (+0) Dex: 10 (+0) Con: 14 (+2) Int: 6 (-2) Wis: 6 (-2) Cha: 7 (-2)
Skills: Damage Vulnerabilities: Fire Damage Resistances: Acid Damage Immunities: Poison Condition Immunities: Poisoned, Prone Languages: None Challenge 2 (450 XP)

Traits:
Non-newtonian: Slimes exist as a non-newtonian fluid with high viscosity. If a slime is hit too hard, the fluid hardens and negates all damage. When an attack roll is made against a slime, if the attack roll is equal to or higher than the AC Non-newtonian triggers. However if the attack roll is lower than the AC it will hit.
Fluid: Slimes leave behind a trail of themselves when they move that evaporates after 6 seconds (1 round). Creatures take 1d4 acid damage for every 5 ft. they travel through the trail.
Viscous: When a slime is damaged using a physical or force attack roll 1d10, on a 4 or higher a small piece of them is flung 5-20 ft. (5 * 1d4 ft.) in the direction of the attack.
Actions:
Erode: Range: 5 ft. Melee attack. -1 to hit. The green slime splashes some of itself onto a creature within range dealing 1d4 + 2 acid damage.
Contaminate: Range: 5 ft. The green slime splashes some of itself onto the ground in a 5 ft. radius, contaminating it for 2 rounds. Creatures take 1d4 acid damage for every 5 ft. they travel through the contaminated area. Any creature within range must make a DC 12 Dex save. On a failed save they take 1d4 acid damage, they take no damage on a successful save
Reform: Range: 5 ft. The green slime reforms with a flung off piece, regaining 1d4 health.
Legendary actions:
The green slime gets 1 legendary action.
Acid shell: The next time the green slime is attacked and takes damage using a physical of force attack the attacker takes 1d4 acid damage. Viscous cannot trigger when acid shell is active. Acid shell cannot be used when it is already active.
Hardened: The green slime drops its AC by 2 until the end of their turn.