Amorphous Golem

Power core: To destroy the power core, make a DC 17 Dexterity check weapon attack. On a success, the golem is destroyed if it is not stacked, otherwise, the core is destroyed and the creature takes damage equal to its average health and loses 1 stack. On a fail, the golem resists any damage that may have been dealt due to its rune. There is 1 power core in each individual golem. Dealing damage normally will also destroy the core.

Slam. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d6 + 1) bludgeoning damage. Slam will deal 1 additional damage for each time it has stacked.

Stack: The base Amorphous Golem has no stacks on it. If 2 Amorphous Golems are within 5 feet of eachother, 1 may use their action to morph into the other, making it slightly larger. Each time a golem stacks, both creatures involved add their maximum and current HP into 2 pools respectively. For every stack, the creature's strength score increases by 1 (diminishing returns may apply at higher stack counts). Every time the maximum health pool is reduced by the average number of hit points, 1 stack is lost and power core is destroyed. This also causes the maximum HP pool to drop by the appropriate amount. The Amorphous Golem becomes Large after 2 stacks and Huge after 5 (Size up to DM's discretion).

Arm Cannon: Ranged Weapon Attack: 15-foot long and 5 foot wide line template. The golem morphs one of its arms into the shape and size of an unstacked Amorphous Golem and swings it off, disconnecting it from the body. May only be used if creature has at least 4 stacks and 1 stack is lost after action is resolved and may be used as a bonus action if stack was used on the same turn. The stacked golem's maximum and current HP will drop by its average HP. All creatures in the line must make a Dexterity saving throw at DC 13. The closest creature in the line takes 3d6 bludgeoning damage on a failed save or half as much damage on a successful one. All other creatures in line take half as much damage on a failed save or no damage on a successful one. All creatures who failed their save are pushed back to the end of the line. The thrown Amorphous Golem will spawn at the end of the line, prone, and dealt damage equal to the creature it first hit (ignoring bludgeoning damage resistance).