Flesh Golem

Flesh Golem CR: 5

Medium construct, neutral

Armor Class: 9

Hit Points: 93 (11d8 + 44)

Speed: 30 ft

STR

19 +4

DEX

9 -1

CON

18 +4

INT

6 -2

WIS

10 +0

CHA

5 -3

Damage Immunities: Lightning, Poison, Bludgeoning, Piercing, and Slashing from nonmagical attacks not made with adamantine weapons

Condition Immunities: Charmed, Exhaustion, Frightened, Paralyzed, Petrified, Poisoned

Senses: Darkvision 60 ft, passive Perception 10

Languages: Understands the languages of it's creator but can't speak

Challenge Rating: 5

Berserk. Whenever the golem starts it's turn with 40 hit points or lower, roll a d6 1d6 . On a 6, the golem goes berserk. On each of the turns while berserk, the golem attacks the nearest creature it can see. If no creature is near enough to to move to and attack, the golem attacks an object, with preference to objects smaller than itself. Once the golem goes berserk, it continues to do so until it is destroyed or regains all it's hit points. The golem's creator, if within 60 ft of the berserk golem, can try to calm it by speaking firmly and persuasively. The golem must be able to hear it's 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 points or fewer, might go berserk again.
Immutable Form. The golem is immune to any spell or effect that would alter it's 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.
Aversion to Fire. If the golem takes fire damage, it has disadvantage on attack rolls and ability checks until the end of it's next turn.
Lightning Absorption. Whenever the golem is subjected to lightning damage, it takes no damage instead a number of hit points equal to the lightning damage dealt.

Actions

Multiattack. The golem makes two slam attacks.
Slam. Melee Weapon Attack +7 to hit, reach 5 ft, one target. ?Hit 13 2d8+4 bludgeoning damage.

Flesh golems are probably the most disturbing of golems. Made from human or humanoid body parts fixed & sown together, they make for a terrifying sight.