Dragon Eel

Limited Amphibiousness. The dragon eel can breathe air and water, but it needs to be submerged at least once every 6 hours to avoid suffocating.

Shocking Hide. A creature that touches the dragon eel or hits it with a melee attack while within 5 feet of it takes 5 (1d10) lightning damage.

Storm Glide. During storms with ample rain or lightning, the dragon eel gains a flying speed equal to its swimming speed.

Multiattack. The dragon eel makes one Bite attack and one Tail Slap attack.

Bite. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 26 (4d8 + 8) piercing damage plus 5 (1d10) lightning damage, and the target must succeed on a DC 18 Constitution saving throw or become paralyzed 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.

Tail Slap. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 30 (5d8 + 8) bludgeoning damage plus 5 (1d10) lightning damage, and the target must succeed on a DC 18 Strength saving throw or be pushed up to 10 feet away from the eel. The dragon eel can choose to not push a target.

Lightning Breath (Recharge 6). The dragon eel exhales lightning in a 60-foot line that is 5 feet wide. Each target in that line must make a DC 18 Dexterity saving throw, taking 55 (10d10) lightning damage on a failed save, or half as much damage on a successful one.