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.
Not all animate corpses shamble from their graves. Boneless are undead remains devoid of skeletons. Most rise from the bodies of those who've suffered brutal ends, such as deliberate skinning or crushing. Deathless malice infuses what remains, their husks flopping and slithering in pursuit of vengeance or at the whims of sinister masters. Slipping through cracks and under doors, these stealthy undead seek to adorn living frames once more, wrapping themselves around their victims and wringing…