Blisterbomb Frog

Amphibious Urge. Due to its nature in life, the frog is irresistibly drawn to water. Whenever it starts its turn within 30 feet of water in an amount of ten gallons or more, it must make a DC 10 Wisdom saving throw. On a failed save, it must spend all of its movement getting as close to the water as possible. When it comes into contact with 10 or more gallons of water, the water is instantly consumed and the frog must make a DC 10 Constitution saving throw. On a failed save, the frog is reduced to zero hit points and automatically succeeds the saving throw from its Blisterbomb trait. If the frog is submerged in water deeper than 3 feet, it cannot deal fire damage, instead creating thick smoke that obscures the area in which it would do so.

Standing Leap. The frog's long jump is up to 20 feet and its high jump is up to 10 feet, with or without a running start.

Blood Embers. When the frog takes damage of any kind except psychic or fire, each creature within 5 feet of it takes 5 (2d4) fire damage.

Blisterbomb. When the frog is reduced to zero hit points by any means including its Amphibious Urge, it must make a DC 10 Constitution saving throw. On a successful save, the frog explodes, creating a 10-foot radius sphere cloud of thick smoke that obscures the area. On a failed save, the frog explodes, instead creating 10-foot radius sphere fireball. Each creature in that area must succeed a DC 11 Dexterity saving throw, taking 9 (4d4) fire damage and 5 (2d4) poison damage on a failed save, or half as much on a successful one.

Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d6 + 1) piercing damage, and the target is grappled (escape DC 11). Until this grapple ends, the target is restrained, and the frog can't bite another target.

Swallow. The frog 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 frog, and it takes 5 (2d4) fire damage at the start of each of the frog's turns. The frog can have only one target swallowed at a time. If the frog dies, a swallowed creature is no longer restrained by it and can escape from the corpse using 5 feet of movement, exiting prone.

Cinder Breath (Recharge 4–6). The frog exhales ash and cinders in a 15-foot cone. Each creature in that area must succeed a DC 11 Dexterity saving throw, taking 9 (4d4) fire damage on a failed save, or half as much on a successful one. When the frog successfully recharges this ability, it must make a DC 10 Constitution saving throw. On a failed save, it is reduced to zero hit points and automatically fails the saving throw from its Blisterbomb trait.