Flaming sphere

Flaming sphere is a spell that summons a globe of hot flames, which the caster can then move at a speed roughly equivalent to that of a human. The sphere's flames are volatile and any creature caught nearby that is unable to get out of the way is scorched.

Editions
It is a druid, sorcerer and wizard spell in the school of evocation in 3.5 edition, and a wizard spell in the school of conjuration in 4th edition.

Effects
In 3.5 edition, the sphere will last for a few minutes, and lasts longer the more powerful the caster. In 4th edition, the sphere dissipates almost immediately after casting on its own, although with a little effort the wizard can maintain the sphere for several minutes or cause it to flare up again. Once the sphere is gone, however, the wizard is unable to reconjure it without substantial rest.

In 3.5 edition, the sphere burns any flammable material it touches, but does not cause damage by movement, as its surface is spongy. It cannot push other objects aside, but it can float over furniture or low walls.

Materials
The material components are powdered iron, tallow, and brimstone.