Dragon Eel

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

Shocking Touch. A dragon eel's body generates a potent charge of lightning. A creature that touches or makes a successful melee attack against a dragon eel takes 5 (1d10) lightning damage.

Storm Glide. During storms, the dragon eel can travel through the air as if under the effects of a fly spell, except using its swim 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 1d4 rounds.

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 push the target up to 10 feet away.

Lightning Breath (Recharge 6). The dragon eel exhales lightning in a 60-foot line that is 5 feet wide. Each target in that line takes 55 (10d10) lightning damage, or half damage with a successful DC 18 Dexterity saving throw.