Shambling Mound
Large plant, unaligned Armor Class 15 (natural armor) Hit Points 136 (16d10 + 48) Speed 20 ft., swim 20 ft.
STR DEX CON INT WIS CHA
18 (+4) 8 (−1) 16 (+3) 5 (−3) 10 (+0) 5 (−3) Skills Stealth +2 Damage Resistances cold, fire Damage Immunities lightning Condition Immunities blinded, deafened, exhaustion Senses blindsight 60 ft. (blind beyond this radius), passive Perception 10 Languages — Challenge 5 (1,800 XP) Lightning Absorption. Whenever the shambling mound is subjected to lightning damage, it takes no damage and regains a number of hit points equal to the lightning damage dealt.
Actions
Multiattack. The shambling mound makes two slam attacks. If both attacks hit a Medium or smaller target, the target is grappled (escape DC 14), and the shambling mound uses its Engulf on it. Slam. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) bludgeoning damage. Engulf. The shambling mound engulfs a Medium or smaller creature grappled by it. The engulfed target is blinded, restrained, and unable to breathe, and it must succeed on a DC 14 Constitution saving throw at the start of each of the mound’s turns or take 13 (2d8 + 4) bludgeoning damage. If the mound moves, the engulfed target moves with it. The mound can have only one creature engulfed at a time.