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.