Kyodai Katatsumuri 巨大蝸牛

Large monstrosity, unaligned

Armor Class 17 (chitinous shell)

Hit Points 152 (16d10 + 64)

Speed 20 ft., climb 10 ft.

STR 20 (+5) · DEX 8 (−1) · CON 18 (+4) · INT 2 (−4) · WIS 12 (+1) · CHA 5 (−3)

Saving Throws Con +8, Wis +5

Damage Vulnerabilities fire, radiant

Damage Resistances acid; bludgeoning, piercing, and slashing from non-magical attacks

Condition Immunities prone

Senses blindsight 30 ft., passive Perception 11

Challenge 6 (2,300 XP)

Traits

Shell Armor. The katatsumuri’s shell grants it advantage on saving throws against being pushed, pulled, or knocked prone. While retracted (see Withdraw reaction) its AC becomes 20, but it is incapacitated until the start of its next turn.

Toxic Slime Trail. The ground in a 10-foot-wide path behind the katatsumuri is coated in corrosive mucus and counts as difficult terrain for 1 minute. A creature that enters the trail or starts its turn there must succeed on a DC 16 Constitution saving throw or take 7 (2d6) acid damage and have its speed halved until the start of its next turn.

Moisture-Bound. If the katatsumuri takes fire damage, its Speed is halved and it can’t take reactions until the end of its next turn.

Actions

Multiattack. The katatsumuri makes one Slam attack and one Acid Spit, or it uses Vacuum Suction if available.

Slam. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 15 (2d8 + 6) bludgeoning damage plus 4 (1d8) acid damage. The target must succeed on a DC 16 Constitution saving throw or be poisoned until the end of its next turn.

Acid Spit. Ranged Weapon Attack: +5 to hit, range 30/60 ft., one target. Hit: 13 (3d6 + 3) acid damage, and non-magical metal objects worn or carried by the target take a permanent –1 penalty to AC or damage rolls (DM’s discretion). An object is destroyed if the penalty equals –5.

Vacuum Suction (Recharge 5–6). The katatsumuri inhales mightily toward one Large or smaller creature within 15 ft. The target must make a DC 16 Strength saving throw. On a failure, it is pulled into the shell, is blinded and restrained, and takes 10 (3d6) acid damage at the start of each of the katatsumuri’s turns. A swallowed creature can escape if it deals 15 slashing damage to the shell’s interior (AC 14); the katatsumuri then regurgitates the creature, which falls prone in a space within 10 ft. of the snail. The katatsumuri can have only one creature swallowed at a time.

Reactions

Withdraw. When the katatsumuri is hit by an attack, it can retract partway into its shell, gaining a +3 bonus to AC against that attack (possibly causing it to miss). Until the start of its next turn, its speed becomes 0.

Lore

A giant snail that can suck a person into its shell or ruin entire fields.

Kyodai Katatsumuri translates literally as “Giant Snail.” Legends portray it as a creature that emits eerie sounds after dark and lays waste to farmers’ fields.

Outwardly the yokai is described as an oversized African land snail: a body stretching ten to sixteen feet (3–5 m) long, a massive, fleshy foot coated in toxic mucus, and an extremely durable spiral shell. Its main anatomical anomaly is an enlarged mantle cavity that can create a vacuum and suck a victim into the shell, where a person or large animal is slowly dissolved by digestive fluids. The shell is almost impervious to stabbing or slashing weapons. While the slime corrodes both organic matter and metal, causes paralysis and, as the creature moves, bonds the soil into a sticky mire that makes maneuvering difficult.

From Yokai Bestiary 5E, Book Two, p. 62 · Fern Flower Press