The Decapus for D&D 5e

The Tortle Package from DM's Guild includes information on a region in Tomb of Annihilation, stats for the Tortle race, and a couple of assorted bits and bobs.  To my surprise, the pdf also includes stats for the decapus (that links to the Pathfinder version), the monster first introduced in Palace of the Silver Princess and illustrated on the cover by the legendary Erol Otus:

Love the vibrant, unwholesome Erol Otus colors.

The fifth edition version of the decapus is large — both AD&D and Pathfinder list the size as "medium," although that Erol Otus picture suggests it's probably "large" — and basically attacks as one would expect.  It clings to walls and swings from trees, grabbing prey with its tentacles and biting them.  It deals more damage when it's climbing and more of its tentacles are free.

However, the original is described as being intelligent; both AD&D and Pathfinder suggest it's of average intelligence, an ambush predator with the capacity for human tactics.  (Pathfinder also gives it the ability to mimic sounds it hears, which is incredibly cool.)  Very different from the large, agile predator in the Tortle Package.

It just so happens that I cobbled together stats for the decapus over a month ago for a game I'm going to run over the holidays, and so I'll present them here.  These stats are partially adapted from both the Pathfinder version (above) and 5e SRD version.  This version of the decapus is smaller and not as tough as the official 5e version, but played correctly, is potentially scarier as it creeps around, making noises to attract the PCs and then picking them off one-by-one.

Pick the one you want, or use both.  Maybe the "official" version is some throwback (a dire decapus?), with the more intelligent version being a highly-evolved specimen.

Decapus

"Decapi are solitary creatures that dwell in ruins, caverns, or dense forest (where their climbing ability gives them great mobility through the tree canopy for pursuing prey or evading predators). On the ground, decapi are slow-moving, so they spend most of their time among the tree tops or hanging from ceilings.

"As nocturnal hunters, decapi are quite fond of human, elf, and halfling flesh. When food is scarce, they can exist on a diet of rats, snakes, and other small creatures or dungeon denizens.

"Decapi prefer a solitary life; the only time more than one will ever be encountered together is during their infrequent mating season. Young decapi are born live, and the female gives birth to only a single young decapus during each mating season. If food is extremely scarce, some decapus females have been known to eat their young.

"This creature’s body is a 4-foot-diameter globe of pallid green. Some have been reported with purple or yellow coloring, but they are rare. Dark brown or black hair grows in seemingly random patches. Regardless of its body color, each decapus has 10 tentacles similar to an octopus’s protruding from its spherical body. Each tentacle is covered in suction cups that aid the creature in climbing and moving trees, but also in catching and killing its prey. Its large wide maw sports sickly yellow teeth and foul breath. Decapi seem to be able to speak with others of their kind using guttural noises."

(In the AD&DMonstrous Manual, the decapi language is described as clicking and body movement.)

A decapus hunts with its mimicry ability. When it senses potential prey nearby, it emits sound intended to draw unwary creatures within reach of its tentacles. Usually this involves a creature that will elicit sympathy from the prey being threatened somehow. For example, when typical humanoid adventurers approach, the decapus is likely to create the sounds of a child surrounded by hungry wolves or of a young woman or man being terrorized by bandits.

Medium aberration, chaotic evil

Armor Class 15 (natural armor)

Hit Points 44 (8d8+8)

Speed 10 ft., climb 30 ft.

Str 16 (+3), Dex 13 (+1), Con 15 (+2), Int 10 (+0), Wis 11 (+0), Cha 12 (+1)

Skills Deception +3, Stealth +3

Senses darkvision 60 ft., passive Perception 10

Languages Decapus

Challenge 2 (450 XP)

Brachiation.  A decapus can move through trees at its climb speed (30 feet per round) by using its tentacles to swing from tree to tree, provided the trees are no more than 10 feet apart.

Mimicry.  A decapus can mimic any sounds it has heard, including voices.  A creature that hears the sounds can tell they are imitations with a successful DC 13 Wisdom (Insight) check.

Actions

Multiattack.  The decapus makes four tentacle attacks.

Tentacles.  Melee Weapon Attack: +5 to hit, reach 5 ft., one target.  Hit: 6 (1d6+3) bludgeoning damage, and the target is grappled (escape DC 13).  The decapus can grapple up to four targets in this fashion, grappling a single target with every pair of tentacles.