Dagger

Melee Weapon Attack: +7 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 7 (1d4 + 5) piercing damage.

Vortex (1/Day)

A boloti can transform into a vortex of swirling, churning water for up to 4 minutes. This ability can be used only while the boloti is underwater, and the boloti can't leave the water while in vortex form. While in vortex form, the boloti can enter another creature's space and stop there in vortex form. In this liquid form, the boloti still takes normal damage from weapons and magic. A creature in the same space as the boloti at the start of the creature's turn takes 9 (2d8) bludgeoning damage unless it makes a successful DC 15 Dexterity saving throw. If the creature is Medium or smaller, a failed saving throw also means it is grappled (escape DC 11). Until this grapple ends, the target is restrained and unable to breathe unless it can breathe water. If the saving throw succeeds, the target is pushed 5 feet so it is out of the boloti's space.