Coagulated Mass

Thick Membrane: The coagulated mass has resistance to all forms of magically sourced damage due to a thick, strange membrane that lines the outside. (force exception)

Unstable form: The coagulated mass is made of various blood and guts in a loosely blob shaped form. this form is weak to impacts, making it take double falling damage and vulnerability to bludgeoning. 

Blood Absorber: When the coagulated mass attacks a being that has blood, it will heal half of the damage dealt. it can gain over-health this way, although, it will burst if it exceeds it's original hp by 1.5 times.

Tentacle Lash: The mass forms a tentacle of blood, using it like a whip to lash at their foe. (+4 to hit) (reach: 10ft) [2d4 + 3] (slashing)

Blood Spear: The mass forms a sharp pointed spear inside its body before launching it outwards. (+4 to hit) (range: 40ft) [3d4 + 3] (piercing)

Blood Explosion: Every long dead blood cell inside the mass becomes incredibly active, vibrating aggressively before they burst in an explosion of acidic blood. (15ft aoe sphere) [dc: 16 dex save] [3d6+ 5] (acid) THIS IS A SELF DESTRUCT.

Merge: Two coagulated mass can merge together, combining their max health and adding an extra dice to all damage rolls. this can happen until the creature becomes massive (this will be a separate monster.)

Blood spray: When damaged by a melee attack, the mass will spray acidic blood onto its attacker. [dc: 14 dex save] [2d4 +2] (acid)