Iron Golem
Large construct, unaligned
Armor Class 20 (natural armor)
Hit Points 252 (24d10 + 120)
Speed 30 ft., swim 15 ft., climb 15 ft.
str
24 (+7)
dex
9 (-1)
con
20 (+5)
int
3 (-4)
wis
11 (+0)
cha
1 (-5)
Damage Immunities fire, poison, psychic
Condition Immunities charmed, exhaustion, frightened, paralyzed, petrified, poisoned
Senses darkvision 120 ft., passive Perception 10
Languages Understands Common plus two other languages but can't speak
Challenge 16 (15,000 XP)
Fire Absorption. Whenever the golem is subjected to Fire damage, it regains a number of Hit Points equal to the Fire damage dealt.
Immutable Form. The golem can't shape-shift.
Magic Resistance. The golem has Advantage on saving throws against spells and other magical effects.
Actions
Bladed Arm. Melee Attack Roll: +12, reach 10 ft. 20 (3d8 + 7) Slashing damage plus 10 (3d6) Fire damage.
Fiery Bolt. Ranged Attack Roll: +10, range 120 ft. 36 (8d8) Fire damage.
Multiattack. The golem makes two attacks, using Bladed Arm or Fiery Bolt in any combination.
Poison Breath. Constitution Saving Throw: DC 18, each creature in a 60-foot Cone. Failure: 55 (10d10) Poison damage. Success: Half damage.