Beelezebub

Acidic Blood. When attacked with a melee weapon the attacker must make a dex save or take 2d4 acid damage, aswell as thier weapon takes 1 damage counter. If the weapon has 5 damage counters it melts.

Destroy Carapice.  Every 10% health lost, Beelezebub loses 1 ac.

Acid Rain. Makes a portion of the terrain acidic, causing it to deal 1d4 per turn started in the portion, aswell as being considered difficult terrain. .

Sting. Melee Attack: +2 to hit, reach 5 ft., 1 target. Hit: (1d12) piercing damage. DC 16 Con save or (1d6 + 4) poison damage 

Bite. Melee Attack: +2 to hit, reach 5 ft., 1 target. Hit: (1d10) piercing damage. DC 14 Dex save or swallowed.

While swallowed take 1d6 poison damage per turn started swallowed, or half as much on a successful DC 14 con save.

Acid Spit. Ranged Attack: + 4 to hit, range 60 ft., DC 16 dex save.Hit:  2d8 acid damage, next turn another 1d4.

Summon 1d4 giant insects.

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Regenerate Carapace(Costs 3 Actions). Heal 2d8 and regain all Ac.