Animated Rock Oil

Amorphous. The animated oil can move through a space as narrow as 1 inch wide without squeezing.

Flammable. If the oil takes fire damage, it starts burning. The burning oil takes 5 fire damage at the start of each of it’s turns (this damage is not affected by vulnerability). Additionally the burning oil deal’s 2d4 fire damage on its slam attacks and to a creature grappled by it at the start of each of it’s turns.

Slam. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 3 (1d6) bludgeoning damage, and the target is grappled if its size medium or smaller. The grappled creature can repeat the saving throw on each of it’s turns to end the effect. Until this grapple ends, the creature is restrained, and the oil can’t grapple another target (but can still use it’s slam attack).