Multiattack

The malleable makes four flesh tendril attacks.

Flesh Tendril

Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 25 (5d6 + 8) bludgeoning damage. If the target is a creature, it is grappled (escape DC 18).

Psychic Drain

One creature grappled by the malleable must make a DC 18 Intelligence saving throw, taking 72 (16d8) psychic damage on a failed save, or half as much damage on a successful one. The target's hp maximum is reduced by an amount equal to the damage taken. This reduction lasts until the target finishes a long rest. The target dies and becomes a minor malleable if this effect reduces its hp maximum to 0.

Separate Malleables

The massive malleable can split into sixteen minor malleables, four moderate malleables, or two major malleables. The new malleables' hp totals are equal to the massive malleable's hp total divided by the number of malleables created (rounded down) and are affected by any conditions, spells, and other magical effects that affected the massive malleable. The new malleables act on the same initiative count as the massive malleable and occupy any unoccupied space that previously contained the massive malleable.