Blood Golem

Immutable Form. The golem is immune to any spell or effect that would alter its form.

Magic Resistance. The golem has advantage on saving throws against spells and other magical effects.

Magic Weapons. The golem's weapon attacks are magical.

• Blood Ooze. The blood golem takes up its entire space. Other creatures can enter the space, but a creature that does so is subjected to the blood golem’s Engulf and has disadvantage on the saving throw. Creatures inside the blood golem can’t be seen and have total cover. A creature within 5 feet of the blood golem can take an action to pull a creature or object out of the cube. Doing so requires a successful DC 12 Strength check, and the creature making the attempt takes 10 (3d6) necrotic damage. The blood golem can hold only one Large creature or up to four Medium or smaller creatures inside it at a time.
• Blood Sense. The blood golem can magically sense the presence of blood in living creatures up to 1 mile away. It knows the general direction they’re in but not their exact locations.
• Blood Splatter. Any time the golem is hit in combat, a gout of blood erupts from its body. All creatures within 10 feet of the golem must succeed on a DC 15 Dexterity saving throw or be blinded until the end of the creature’s next turn.
• Berserk. When the blood golem starts its turn with 40 hit points or fewer, roll a d6. On a 6, the golem goes berserk. On each of its turns while berserk, the golem attacks the nearest creature it can see. If no creature is near enough to move to and attack, the golem attacks an object, with preference for an object smaller than itself. Once the blood golem goes berserk, it continues to do so until it is destroyed or regains all its hit points. The golem’s creator, if within 60 feet of the berserk golem, can try to calm it by speaking firmly and persuasively. The golem must be able to hear its creator, who must take an action to make a DC 15 Charisma (Persuasion) check. If the check succeeds, the golem ceases being berserk. If it takes damage while still at 40 hit points or fewer, the golem might go berserk again.

Multiattack. The golem makes two slam attacks.

Slam. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 13 (2d8 + 4) bludgeoning damage, and the target must make a DC 15 Constitution saving throw. On a failed save, the target takes 22 (4d8 + 4) bludgeoning damage plus 14 (3d6 + 4) necrotic damage; its hit point maximum is reduced by the amount equal to the necrotic damage, and the blood golem regains hit points equal to that amount. The reduction in the target’s hit point maximum lasts until the target finishes a long rest. The Golems target dies if this reduces its hit point maximum to 0.

Engulf. The blood golem moves up to its speed. While doing so, it can enter Large or smaller creatures’ spaces. Whenever the blood golem enters a creature’s space, the creature must make a DC 12 Dexterity saving throw. On a successful save, the creature can choose to be pushed 5 feet back or to the side of the blood golem. A creature that chooses not to be pushed suffers the consequences of a failed saving throw. On a failed save, the blood golem enters the creature’s space, and the creature takes 10 (3d6) necrotic damage and is engulfed. The engulfed creature can’t breathe, is Restrained, and takes 21 (6d6) necrotic damage at the start of each of the blood golem’s turns. When the blood golem moves, the engulfed creature moves with it. An engulfed creature can try to escape by taking an action to make a DC 12 Strength check. On a success, the creature escapes and enters a space of its choice within 5 feet of the blood golem.