Traits

Amphibious. Gonggong can breathe air and water.

Floodwalker. Nonmagical difficult terrain made of mud or water costs Gonggong no extra movement.

Actions

Multiattack. Gonggong makes two Flood Staff attacks.

Flood Staff. Melee Weapon Attack: +12 to hit, reach 15 ft., one target. Hit: 23 (3d10 + 7) bludgeoning damage. The target must succeed on a DC 20 Strength saving throw or be pushed 15 feet.

Broken River (Recharge 5–6). A wave fills a line 60 feet long and 15 feet wide. Each creature in it makes a DC 19 Strength saving throw, taking 45 (10d8) bludgeoning damage on a failure or half on a success. On a failure, it is also pushed 20 feet and knocked prone.

Bonus actions

Rising Water. A 15-foot square of ground within 60 feet becomes difficult terrain until the start of Gonggong’s next turn.

Reactions

Undertow. When a creature within 15 feet moves away from Gonggong, it must succeed on a DC 19 Strength saving throw or its speed becomes 0 for the rest of that turn.