5e Monster: Aberrant Tapeworm

The Aberrant Tapeworm

Generic, right? There really is no better way to describe this thing. It's nice and understated, fitting somewhere between somewhat ominous and extremely inconvenient.

The Aberrant Tapeworm is a parasite. It's introduced to the host through undercooked meat when animals graze in corrupted fields, but you can change that to whatever. In my campaign, an Inquisitor ate a wild hog that ate some weeds in the field the Inquisitor murdered his wife.

While typical tapeworms seek sustenance through absorbing nutrients, Aberrant Tapeworms multiply inside the host, introducing foreign agents into the bloodstream that induce rage and paranoia. People will observe worrisome mood changes in the afflicted, but will often be murdered by the host before having a full grasp on what's happening. As they grow and replicate (over 5-6 days), they maneuver to the brain and sieze control of the host's body. When this happens, they devour organs and use their inherent telekinetic abilities to manipulate their victim's lifeless body. The Aberrant Tapeworm's waste is emitted in the form of a gas, equivalent to a Cloudkill, which is mostly confined to the body.

By the 7th day (for a full sized adult), the body will be too small to contain the parasite. If either the body is too small or the host is under attack, the parasite will expand to its full size (3 times larger than it was inside the body), bursting open the host's body and releasing the Cloudkill gas as well as its hatchlings (d6+2 after 6 days).

Exposure to fresh air increases the growth of the parasite. Every round of exposure increases its size category, capping at gargantuan. Sunlight directly harms the parasite, dealing 2d6 radiant damage and causing a 1 in 6 chance that the parasite catches flame.

In appearance, the parasite is a midnight black slick-bodied worm with a mass of tentacles stretching throughout its body and a massive mouth with rows of vicious teeth. It will use the host's remains as a shield.

Tactically, it will try to draw its victims into confined spaces if it feels threatened. It will use its telekinetic abilities to move debris and block exits so that enemies will die of poisoning, making them easy to consume.

The Stat Block

6th+ Day Aberrant Tapeworm (Large Aberration, Chaotic Evil)

Armor Class: 24 with Corpse Shield, 22 without

Size: Large 15d8+107 (172 HP average)

Speed: 30 ft, 30 feet burrow.

22 STR (+6), 14 DEX (+2), 24 CON (+7), 20 INT (+5), 8 WIS (-1), 16 CHA (+3)

Languages Known: Anything the host knew. Telepathy 90 ft.

Senses: Blindsense 120ft, none else (senses movement and vibrations), 15 Passive Perception (advantage based on movement)

Vulnerability (Damage): Fire, Radiant.

Resistances (Damage): Nonmagical bludgeoning.

Immunities (Damage): Poison

Immunities (Conditions): charmed, exhaustion, frightened, poisoned.

Saving Throws: +12 Strength, +13 CON, +11 INT.

Proficiencies: +9 Deception, +5 Insight, +5 Perception, +12 Athletics.

Actions

Telekinesis: The Tapeworm can move up to 500 pounds of objects up to 30 feet. Telekinesis used on a creature requires a failed saving throw of DC20 Strength.

Multi-attack: The Tapeworm can make two tentacle attacks and can make a bite attack if one of the tentacle attacks hit OR they can make two tentacle attacks and use their telekinesis.

Tentacle: +12 to hit, 2d10+6 bludgeoning damage and the target is grappled (DC 20 Strength or Dexterity to escape). A successful tentacle attack on a grappled creature becomes a restraining. Up to 3 medium sized creatures can be held by tentacles at a time.

Bite: +12 to hit (automatic during restraint), 2d6+6 piercing damage and DC20 CON save, taking 4d6 acid damage, halved on a successful save.

Swallow: A restrained creature that has already been bitten must making a DC20 Strength Save or be swallowed by the Tapeworm. They will continue to be  restrained and will suffer the effects of a Bite every round that they are swallowed. Only one medium sized creature or two small creatures can be swallowed at a time.

In the event that a Druid wildshapes into a larger creature inside of the Tapeworm, the Tapeworm will spit them out to prevent overstretching.

Recharge 5-6: Cloudkill, activated automatically when bursting from host

Legendary Actions (3 per round)

Legendary Resistance (3x per day)

Bite (1 LA)

Tentacle (1 LA)

Swallow (1 LA)

Breathe (2 LAs): The Tapeworm breathes in the Cloudkill and all of the air around it, growing 1 size category. All attacks get an additional +2 to hit and damage and Tapeworm gets 24 temp HP.

Baby Aberrant Tapeworms only have 2d4+2 HP, 10 speed, and try to burrow into the skin of their victims, which takes 1 full round after they commit to the action. A Cure Disease effect will kill the Baby Aberrant Tapeworm.