Tiermann's World was a frozen forest planet owned and inhabited by Ernest Tiermann and his family, the sole human inhabitants. They shared the planet with native sabre-toothed tigers, horned bears, and giant albino bats.
At some point, the humans were driven away when the Voracious Craw began consuming their planet and their dreamhome rebelled against them. Ultimately, the Tenth Doctor, Martha, and Solin Tiermann drove the Craw away by mimicking the sound of a larger Craw. (PROSE: Sick Building)