Adult Prismatic Slime

Acid Spit. Range Attack: +5 to hit, range 20 ft., one creature. Hit: The target must succeed on a DC 15 Dexterity saving throw or take 18 (4d8) acid damage, half as much on a save

Innate Spellcasting (1/Day): The slime’s innate spellcasting ability is Charisma (spell save DC 15). It can cast the following spells without requiring any components:

• Seeming
• Hallucinatory Terrain

Innate Spellcasting (4/Day): The slime’s innate spellcasting ability is Charisma (spell save DC 15). It can cast the following spells without requiring any components:

• Mirror Image
• Phantasmal Killer

Innate Spellcasting (8/Day): The slime’s innate spellcasting ability is Charisma (spell save DC 15). It can cast the following spells without requiring any components:

• Major Illusion
• Phantasmal Force
• Color Spray

Illusory Ensnarement (1/Day): As an action, the adult slime weaves an intricate and powerful illusion of safety and comfort around a target within 30 feet that it can see. The target must make a Wisdom saving throw against a DC 23. If the target is currently engaged in combat, it has advantage on the saving throw. If the target is not in combat, it has disadvantage on the saving throw. On a failed save, the target becomes ensnared in the illusion, believing it is safe and secure.

Effect: While ensnared, the target perceives its surroundings as idyllic and free from danger. It is unable to take any hostile actions, and it has disadvantage on Perception checks to detect threats. The target remains unaware of its true situation until the effect ends. On a failed save, A large or smaller target is engulfed by the adult slime, and the slime begins its digestive process. The target takes 20 (4d10) acid damage at the start of each of its turns while engulfed. The target can use its action to attempt to break free of the illusion with a DC 17 Wisdom saving throw, then it can use an action to break free of the slime by making a Strength (Athletics) or Dexterity (Acrobatics) check against the slime’s Athletics check DC 15.

Duration: The ensnarement effect lasts for 1 minute per 100 pounds of organic matter. If the creature is still alive, it wakes from the illusion and has advantage on the saving throw to break free.
Restrictions:
• The adult slime can use this ability only once per day.
• While maintaining the master illusion, the adult slime cannot cast additional spells or use other abilities.

Distracting Mirage (Reaction). The slime can create a mirage that obscures its true position. As a reaction when it’s hit by an attack, it can create a duplicate of itself in a nearby square. The attacker has disadvantage on their next attack roll against the slime.

 

Rainbow Radiance (Reaction). The slime can cast this as a reaction when a melee attack is made against it or an ally within 15 feet of the slime. The attacker rolls at disadvantage on the attack. The slime creates a mesmerizing pattern like oil on water across its surface or glowing orbs of a similar effect that hover in the air for the duration. You can also combine the four lights into one glowing vaguely slime form of Medium size. Whichever form you choose, each light sheds dim light in a 20-foot radius.