Candy Corn Golem

Berserk. Whenever the 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 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.

Aversion of Fire. If the golem takes fire damage, it has disadvantage on attack rolls and ability checks until the end of its next turn.

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

Lightning Absorption. Whenever the golem is subjected to lightning damage, it takes no damage and instead regains a number of hit points equal to the lightning damage dealt.

Magic Resistance. The golem has advantage on saving throws against spells and other magical effects. Fire Based magical attacks do not roll with advantage. 

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

Multiattack. The golem makes two slam attacks. Or one Slam and one Bite attack. 

Slam. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) bludgeoning damage.

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 4 (1d6 + 4) piercing damage, and the target is grappled (escape DC 14). Until this grapple ends, the target is restrained, and the Golem can't bite another target.

Swallow. The Candy Corn Golem makes one bite attack against a Small or smaller target it is grappling. If the attack hits, the target is swallowed, and the grapple ends. The swallowed target is blinded and restrained, it has total cover against attacks and other effects outside the Golem, and it takes 5 (2d4) Fire damage at the start of each of the Golem's turns while inside its molten sugar interior. The Candy Corn Golem can have only one target swallowed at a time. If it dies, a swallowed creature is no longer restrained by it and can escape from the corpse using 5 feet of movement, exiting prone.