Beholder Flail Snail

Antimagic Shell. The snail has advantage on saving throws against spells, and any creature making a spell attack against the snail has disadvantage on the attack roll. If the snail succeeds on its saving throw against a spell or a spell attack misses it, an additional effect might occur, as determined by rolling a d6.

1–2. If the spell affects an area or has multiple targets, it fails and has no effect. If the spell targets only the snail, it has no effect on the snail and is reflected back at the caster, using the spell slot level, spell save DC, attack bonus, and spellcasting ability of the caster.

3–4. No additional effect.

5–6. The snail’s shell converts some of the spell’s energy into a burst of destructive force. Each creature within 30 feet of the snail must make a DC 15 Constitution saving throw, taking 1d6bforce damage per level of the spell on a failed save, or half as much damage on a successful one.

Flail Tentacles. The flail snail has five flail tentacles. Whenever the snail takes 10 damage or more on a single turn, one of its tentacles dies. If even one tentacle remains, the snail regrows all dead ones within 1d4 days. If all its tentacles die, the snail retracts into its shell, gaining total cover, and it begins wailing, a sound that can be heard for 600 feet, stopping only when it dies 5d6 minutes later. Healing magic that restores limbs, such as the regenerate spell, can halt this dying process.

Multiattack. The flail snail makes as many Flail Tentacle attacks as it has flail tentacles, all against the same target.

Flail Tentacle. Melee Weapon Attack. + 7 to hit. Range 10 ft

1. Charm Flail. The targeted creature must succeed on a DC 16 Wisdom saving throw or be charmed by the beholder for 1 hour, or until the flail snail harms the creature.
2. Paralyzing Flail. The targeted creature must succeed on a DC 16 Constitution saving throw or be paralyzed for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
3. Fear Flail. The targeted creature must succeed on a DC 16 Wisdom saving throw or be frightened for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
4. Slowing Flail. The targeted creature must succeed on a DC 16 Dexterity saving throw. On a failed save, the target’s speed is halved for 1 minute. In addition, the creature can’t take reactions, and it can take either an action or a bonus action on its turn, not both. The creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
5. Enervation Flail. The targeted creature must make a DC 16 Constitution saving throw, taking 36 (8d8)necrotic damage on a failed save, or half as much damage on a successful one.
6. Telekinetic Flail. If the target is a creature, it must succeed on a DC 16 Strength saving throw or the beholder moves it up to 30 feet in any direction. It is restrained by the flails telekinetic grip until the start of the flail snails next turn or until the flail snail is incapacitated.
   If the target is an object weighing 300 pounds or less that isn’t being worn or carried, it is moved up to 30 feet in any direction. The flail snail can also exert fine control on objects with this ray, such as manipulating a simple tool or opening a door or a container.
7. Sleep Flail. The targeted creature must succeed on a DC 16 Wisdom saving throw or fall asleep and remain unconscious for 1 minute. The target awakens if it takes damage or another creature takes an action to wake it. This ray has no effect on constructs and undead.
8. Petrification Flail. The targeted creature must make a DC 16 Dexterity saving throw. On a failed save, the creature begins to turn to stone and is restrained. It must repeat the saving throw at the end of its next turn. On a success, the effect ends. On a failure, the creature is petrified until freed by the greater restoration spell or other magic.
9. Disintegration Flail. If the target is a creature, it must succeed on a DC 16 Dexterity saving throw or take 45 (10d8) force damage. If this damage reduces the creature to 0 hit points, its body becomes a pile of fine gray dust.
   If the target is a Large or smaller nonmagical object or creation of magical force, it is disintegrated without a saving throw. If the target is a Huge or larger object or creation of magical force, this ray disintegrates a 10-foot cube of it.
10. Death Flail. The targeted creature must succeed on a DC 16 Dexterity saving throw or take 55 (10d10)necrotic damage. The target dies if the ray reduces it to 0 hit points.

Scintillating Shell (Recharges after a Short or Long Rest). The snail’s shell emits dazzling, colored light until the end of the snail’s next turn. During this time, the shell sheds bright light in a 30-foot radius and dim light for an additional 30 feet, and creatures that can see the snail have disadvantage on attack rolls against it. In addition, any creature within the bright light and able to see the snail when this power is activated must succeed on a DC 15 Wisdom saving throw or be stunned until the light ends.

Shell Defense. The flail snail withdraws into its shell, gaining a +4 bonus to AC until it emerges. It can emerge from its shell as a bonus action on its turn.