Actions

Multiattack. The oni can make an attack with its giant kanabō or two slam attacks.

Giant Kanabō. Melee Weapon Attack: +12 to hit, reach 10', one target. Hit: 20 (3d6 + 9) 3d6+9 bludgeoning damage & the creature must succeed on a DC 20 Constitution saving throw or fall prone.

Slam. Melee Weapon Attack: +11 to hit, reach 5', one target. Hit: 13 (2d4 + 8) 2d4+8 bludgeoning damage. If the creature is size Large or smaller, it must succeed on a DC 19 Constitution saving throw or be knocked 10' away from the oni.

Change Shape. The oni magically polymorphs into a Small or Medium humanoid, or back into its true form. Other than its size, its statistics are the same in each form. Any equipment it is wearing or carrying isn't transformed but appears appropriately sized to its current form.

Bonus Actions

Jishin (Recharge 5-6). The oni can cause an earth tremor, choosing either to effect everything within 5' of itself or in a 30' line extending out from itself. Any creature in the affected area must succeed on a DC 20 Constitution saving throw or be knocked prone & take 1d4 bludgeoning damage. Genso oni are immune to this ability.

Suggested Environments

Hills, Mountains