Fire elemental

From Tardis Wiki, the free Doctor Who reference

A fire elemental was a creature from an o-region which hid in light particles that travelled to Siberia in 1894. Following the destruction of the ice in the cave in which it landed, the creature burrowed down through the arctic tundra to magma under the Earth's crust. The elemental then merged with the lava. (PROSE: Time Zero)

The creature emerged from the Earth's crust in Middletown at the end of the 19th century. The fire elemental encountered the Eighth Doctor, who killed the creature by a huge flood released by the destruction of the Middletown dam. (PROSE: The Burning)