Keen Smell. The vol-chu has advantage on Wisdom (Perception) checks that rely on smell.

Explode. If the vol-chu is reduced to 0 hit points it explodes with a fiery burst hitting every creature within 5 feet of it dealing 2d6 lightning damage unless they succeed on a DC 13 Dexterity.

Nullification. If the vol-chu is forced into the same space as a terra-chu it is reduced to 0 Hit points without exploding.

Bite. Melee Weapon Attack: +0 to hit, reach 5 ft., one target. Hit: 1 lightning.