Heavy Sleeper. If either of the mound’s forms has been unconscious within the past minute, it can’t use its tentacle attack more than once per turn.
Oozing Body. The flesh mound can move through spaces occupied by enemy creatures, as well as spaces smaller than a Large creature. (It can't end its turn inside an occupied space, and it provokes opportunity attacks normally.)
Innocent Heart. The center of the mound conceals its heart: a large, misshapen rib cage. Within the rib cage hovers the infant corpse of Walter Durst. Walter's corpse has AC 15 and the same ability scores as the flesh mound. Each time Walter's corpse takes damage, the flesh mound takes twice as much damage.
Mother's Lullaby. If a player uses their action to hum or play Waltz for Klara and succeeds on a DC 10 Charisma (Performance) check, the mound exposes its heart and can't use its withdraw reaction until the start of the player's next turn.
Multiattack. The flesh mound makes three attacks, or two attacks if its heavy sleeper feature is active.
Tentacle. Melee Weapon Attack: +5 to hit, reach 15 ft., one target. Hit: 9 (2d6 + 2) bludgeoning damage, or 4 (1d4 + 2) bludgeoning damage if the mound's heavy sleeper. feature is active. If the target is a creature, it must succeed on a DC 13 Strength saving throw or be pulled up to 15 feet toward the mound.
Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (2d4 + 2) piercing damage.
Gore Spray. The mound spews blood and gore in a 15-foot cone. Each creature in that area must make a DC 13 Dexterity saving throw. On a failure, a creature takes 5 (2d4) necrotic damage and is blinded until the end of the mound's next turn. On a success, a creature takes half as much damage and isn't blinded. Using this ability exposes the mound's heart, allowing it to be attacked.
Wail. The infant corpse of Walter Durst releases a piercing shriek. Each creature that can hear the shriek within 30 feet of the mound must succeed on a DC 10 Constitution saving throw or take 2 (1d4) psychic damage and be deafened until the end of the mound's next turn. Using this ability exposes the mound's heart, allowing it to be attacked.
The flesh mound can take up to three reactions per round, though no more than one per turn. If it would lose its reactions and isn't incapacitated, it loses one reaction instead.
Withdraw. In response to an attack or harmful spell hitting or missing its heart, the mound withdraws its heart into its body, concealing it from view and protecting it from attacks.
Lash Out. In response to taking damage from a melee attack, the mound lashes out at the attacker with a tentacle. The attacker must succeed on a DC 13 Dexterity saving throw or be pushed 10 feet away. If the attacker fails the saving throw by 5 or more, they also fall prone.
Roll. In response to taking damage from a ranged attack or spell, the mound moves up to its speed directly toward or away from the attacker without provoking opportunity attacks. If it moves toward the attacker, it can then immediately attempt to shove them.
Heavy Sleeper. If either of the mound’s forms has been unconscious within the past minute, it can’t use its slam attack more than once per turn.
Oozing Body. The flesh mound can move through spaces occupied by enemy creatures, as well as spaces smaller than a Large creature. (It can't end its turn inside an occupied space, and it provokes opportunity attacks normally.)
Instinctual Defense. When the mound drops to 0 hit points, it expels each creature currently engulfed by it. (Those creatures appear prone in an empty space within 5 feet of the mound.) The mound’s statistics are then instantly replaced by the statistics of its second form. Its initiative count doesn’t change. Excess damage doesn't carry over to its new form, but it retains any conditions it had in its previous form.
Multiattack. The flesh mound makes two attacks. It can replace one of those attacks with engulf. If its heavy sleeper feature is active, it can't use its slam attack more than once, and it can't use engulf on the same turn it uses its slam.
Slam. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 8 (2d6 + 1) bludgeoning damage, or 6 (2d4 + 1) bludgeoning damage if the mound's heavy sleeper. feature is active. If the attack hits a Medium or smaller target, the target is grappled (escape DC 13).
Bone Splinters. Ranged Weapon Attack: +5 to hit, range 20/60 ft., up to two targets standing within 5 ft. of each other. Hit: 3 (1d4 + 1) piercing damage.
Engulf. The flesh mound attempts to engulf a Medium or smaller creature grappled by it, forcing that creature to make a DC 13 Strength saving throw. On a failure, the engulfed target is blinded, restrained, and unable to breathe, and it must succeed on a DC 13 Constitution saving throw at the start of each of its turns or take 6 (2d4 + 1) bludgeoning damage. If the mound moves, the engulfed target moves with it. The mound can only have one creature engulfed at a time. An engulfed creature can make a DC 13 Strength saving throw at the end of each of its turns, freeing itself on a success. (Once freed, the creature is no longer grappled.)
Rupture. The flesh mound expels a pustule of rotting flesh, which hits a point within 20 feet of the mound and bursts, spraying each creature within 5 feet with caustic blood and pus. A target must succeed on a DC 13 Constitution saving throw or be poisoned until the start of the flesh mound's next turn.
Quake. The flesh mound slams against the floor, causing the room to quake. Each creature within 10 feet of the mound must succeed on a DC 13 Strength saving throw or fall prone.
The flesh mound can take up to three reactions per round, though no more than one per turn. If it would lose its reactions and isn't incapacitated, it loses one reaction instead.
Squelch. In response to taking damage from a melee attack, the flesh mound attempts to grapple the attacker using their Slam.
Roll. In response to taking damage from a ranged attack or spell, the flesh mound moves up to its speed directly toward or away from the attacker without provoking opportunity attacks.
Compression. The boneless can move through any opening at least 1 inch wide without squeezing. It can also squeeze to fit into a space that a Tiny creature could fit in.
Unusual Nature. The boneless doesn't require sleep.
Multiattack. The boneless makes two Slam attacks. If both attacks hit a Large or smaller creature, the creature is grappled (escape DC 13), and the boneless can use Crushing Embrace.
Slam. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 5 (1d4 + 3) bludgeoning damage.
Crushing Embrace. The boneless wraps its body around a Large or smaller creature grappled by it. While the boneless is attached, the target is blinded and is unable to breathe. The target must succeed on a DC 13 Strength saving throw at the start of each of the boneless' turns or take 5 (1d4 + 3) bludgeoning damage. If something moves the target, the boneless moves with it. The boneless can detach itself by spending 5 feet of its movement. A creature, including the target, can use its action to try to detach the boneless and force it to move into the nearest unoccupied space, doing so with a successful DC 13 Strength check. When the boneless dies, it detaches from any creature it is attached to.