Tiger
Tigers were large predatory cats found in parts of Asia.
Earth tigers
The Tribe of Gum had to defend themselves from tigers amongst other animals. (DW: An Unearthly Child)
Among the prizes that the First Doctor obtained during a game of backgammon against Kublai Khan in the 13th century were twenty-five tigers. (DW: Marco Polo)
In 1988, when the Seventh Doctor and Ace visited Windsor Castle, there was a stuffed tiger head in the basement. (DW: Silver Nemesis)
Tigers went extinct before 2148, though their bones were sometimes preserved and saved. (NA: St Anthony's Fire)
The Siberian tiger was worth 600 points in the I-Spyder Book of Earth Creatures. (NSA: The Last Dodo)
Similar creatures
Despite similar appearances, the tigers of Earth were unrelated to the Hitchemus Tigers. (EDA: The Year of Intelligent Tigers)
There were at least 2 species of shapeshifting tiger-like species: an unnamed species (ST: Old Flames) and the Tygers (TN: Eye of the Tyger). Gideon changed into a Tiger-like humanoid. (DWM: Universal Monsters)