Blighted Froghemoth

Amphibious. The froghemoth can breathe air and water.

Shock Susceptibility. If the froghemoth takes lightning damage, it suffers several effects until the end of its next turn: its speed is halved, it takes a −2 penalty to AC and Dexterity saving throws, it can’t use reactions or Multiattack, and on its turn, it can use either an action or a bonus action, not both.

Multiattack. The froghemoth makes two attacks with its tentacles. It can also use its tongue or bite.

Tentacle. Melee Weapon Attack: +10 to hit, reach 20 ft., one target. Hit: 19 (3d8 + 6) bludgeoning damage, and the target is grappled (escape DC 16) if it is a Huge or smaller creature. Until the grapple ends, the froghemoth can’t use this tentacle on another target. The froghemoth has four tentacles.

Bite. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 22 (3d10 + 6) piercing damage, and the target is swallowed if it is a Medium or smaller creature. A swallowed creature is blinded and restrained, has total cover against attacks and other effects outside the froghemoth, and takes 10 (3d6) acid damage at the start of each of the froghemoth’s turns.

The froghemoth’s gullet can hold up to two creatures at a time. If the froghemoth takes 20 damage or more on a single turn from a creature inside it, the froghemoth must succeed on a DC 20 Constitution saving throw at the end of that turn or regurgitate all swallowed creatures, each of which falls prone in a space within 10 feet of the froghemoth. If the froghemoth dies, a swallowed creature is no longer restrained by it and can escape from the corpse using 10 feet of movement, exiting prone.

Blighted tongue. The froghemoth targets one Medium or smaller creature that it can see within 20 feet of it. The target must make a DC 18 Strength saving throw. On a failed save, the target is pulled into an unoccupied space within 5 feet of the froghemoth, and the froghemoth can make a bite attack against it as a bonus action. When a character is hit by the blighted tongue, A burrowing worm latches onto the target’s skin unless the target succeeded on their Strength saving throw.  The burrowing worm burrows under the target’s skin at the end of the target’s next turn, dealing 1 piercing damage to it. At the end of each of its turns thereafter, the target takes 2d6 necrotic damage per worm infesting target (max 10d6). A worm-infested target dies if it drops to 0 hit points, then rises 10 minutes later as a spawn of Kyuss. If a worm-infested creature is targeted by an effect that cures disease or removes a curse, all the worms infesting it wither away.  

The burrowing worm is a tiny undead with AC 6, 1 hit point a 2 (-4) in every ability score, and a speed of 1 foot. While on the targets skin, the burrowing worm can be killed by normal means od scraped off using an action. 

Legendary Resistance (3/Day). If the Blighted Froghemoth fails a saving throw, it can choose to succeed instead.

The Blighted Froghemoth can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The Blighted Froghemoth regains spent legendary actions at the start of its turn.

 1 Action: The creature makes one attack or uses one of its other actions. Or The creature makes a Wisdom (Perception) check.

2 Actions: The Blighted Froghemoth uses its Poison Tentacle touch: Melee Attack: +10 to hit, reach 20 ft., one creature. Hit: 10 (3d6) Acid damage. The target must succeed on a DC 16 Constitution saving throw or be poisoned for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

3 Actions: Breath weapon: Toxic Belch (Recharge 5–6). The Blighted Frohemoth exhales acid in a 60-­foot line that is 5 feet wide. Each creature in that line must make a DC 18 Dexterity saving throw, taking 36 (8d8) acid damage on a failed save, or half as much damage on a successful one.