Mammoth

Mammoths were a species of proboscidean mammal native to Earth in humanity's prehistory. They evolved from elephants which migrated from Africa to the north and adapted to Europe, Northern Asia including Russia, and North America in the Ice Age.

human prehistory
Around 100,000 BC, Martha Jones watched herds of mammoths while the Tenth Doctor went to retrieve the bodies of Modrikanians who had died in a crash on Earth. (NSA: Snowglobe 7)

Nimrod's Neanderthal tribe herded mammoths "sunward to find new grazing." (DW: Ghost Light) According to the Fourth Doctor, the Neanderthals could knock up a good Mammoth casserole. (MA: The Romance of Crime)

While being pursued by the Trods through time, the Second Doctor visited prehistoric Earth, where he used his recorder to befriend a herd of mammoths and get them to destroy the Trods' power supply. (TVC: Pursued by the Trods)

The Ninth Doctor and Rose on a visit to prehistoric Earth encountered a mammoth killed by a Hy-bractor. (NSA: Only Human)

After being flung back in time by a Time Cube, the Fourth Doctor, Sarah Jane and Dr. Bhoul encountered a caveman and a raging mammoth. (DWAN: The Time Snatch)

The Eleventh Doctor and Amy Pond encountered a mammoth in New York. (NSA: The Forgotten Army)

In Malohkeh's data was a picture of a mammoth, suggesting that one was one of his speciemans. (DW: Cold Blood)

Modern times
There were rumours that King George III of the United Kingdom received the last mammoth in Europe as a gift from Catherine II of Russia. In 1782, during a night of drinking with the Eighth Doctor, Scarlette claimed that she had once ridden George III's mammoth. As late as 1804, Thomas Jefferson believed that woolly mammoths still roamed the North American midwest and even sent an expedition to find one. (EDA: The Adventuress of Henrietta Street)

K9 once encountered some mammoths on an unnamed planet in another dimension, partially inhabited by ex-Tellac miners. They lived alongside other Earth animals from widely varying periods of evolutionary history. On this planet, he observed one fighting a sabre-toothed tiger. (AK9: K9 and the Missing Planet)

Alternate timelines
In an alternate timeline, the Silurians brought back the mammoths, raising them for food and allowing them to roam the mountains of Earth. (NA: Blood Heat)

In another alternate timeline, an American news anchor told her audience that the Holy Roman Emperor Winston Churchill had a "personal mammoth", and that he returned to the Buckingham Senate atop it. (DW: The Wedding of River Song)

Other planets

 * A zoo on an unnamed planet exhibited a mammoth or a mammoth-like creature. (TVC: The Didus Expedition)
 * The Junlangis of Dellah were white, mammoth-like creatures. (BNA: Twilight of the Gods)
 * Yahoomer's species resembled orange mammoths with four trunks. (NSA: The Monsters Inside)