Animated coal

 The coals are Tiny animated objects that skip and bounce around.

Throwing a bucket of water on a coal requires a successful ranged attack, and the bucket is treated as an improvised weapon. A bucket of water deals 1d6 damage to a coal. An animated coal that is submerged in water takes the damage at the start of each of its turns until it is no longer submerged. A coal reduced to 0 hit points is inanimate and harmless.

Kindle. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 2 (1d4) fire damage, and the target catches fire if it is flammable. Until a creature takes an action to douse the fire, the target takes 2 (1d4) fire damage at the start of each of its turns.