Death Burst. When the eelfolk dies, it explodes in a burst of pent-up electricity.  Each creature within 10 feet of it must make a DC 12 Dexterity saving throw, taking 7 (2d6) lightning damage on a failed save, or half as much on a successful one.

Hold Breath. The eelfolk can hold their breath for 1 hour.

Lunge. If the eelfolk move at least 20 feet straight toward a target and then hits with a long knife attack on the same turn, the target takes an extra 7 (2d6) piercing damage.

Long Knife. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d6 + 1) slashing damage.