Snowman

Snowmen were sculptures fashioned in the shape of men. They were built of snow, but items were usually added as accessories.

On Earth
In 1892 London, the Great Intelligence brought snowmen to life to take over the world. The snowmen could be summoned if someone was thinking about them, thanks to being made of telepathic snow, but if said person thought about melting the snowmen, they would melt. This army could be advanced into a humanoid form via the Ice Governess' template. However they were melted en masse when the Intelligence's snow form was melted by the Latimer house's sadness. (TV: The Snowmen)

On 1963 Earth, the Cold brought snowmen to life to serve as its army. (PROSE: Time and Relative)

Snowy Boots, a doll resembling a snowman, was the most popular children's toy one Christmas season. (PROSE: Snowman in Manhattan)

The remains of a giant alien mosquito defeated by the First Doctor and Steven Taylor combined with snow and the DNA of two human boys, causing the two snowmen they had made with their mother to come to life. They were rescued from being melted by the sun by the Fifth Doctor, who took them to the North Pole. (PROSE: Do You Smell Carrots?)

When the Council of Dead was planning to sell humans into slavery, they caused a massive snowstorm and set up snowmen as sentries. These snowmen could animate, fly and shoot beams out of their eyes to teleport people. (PROSE: Attack of the Snowmen)

The Snowman was a popular televised Christmas special on Earth about a flying snowman. (PROSE: The Doctor on My Shoulder)

Other locations
Upon exiting the TARDIS, the Sixth Doctor found his coat draped over a snowman, with his umbrella under its arm. Some time later, both the Doctor and Frobisher skidded down a slope before colliding with this snowman. (COMIC: Voyager)

The Demon Magician used his magic to bring to life a snowman. It grabbed John and Gillian, but the First Doctor used his "magic box" to melt the snowman, freeing his grandchildren. (COMIC: A Christmas Story)

The Eleventh Doctor built a number of snowmen in Sardicktown. (TV: A Christmas Carol)

References to snowmen
The planet Reklon, by a coincidence of geology and atmospherics, resembled a huge snowman smoking a pipe and wearing a mauve hat. (PROSE: Sky Pirates!)

The Tenth Doctor, upon recalling a conversation about The Snowman, told Mason Valentin: "I'm the Snowman...and time's up." (PROSE: The Doctor on My Shoulder)

Alternate timelines
In an alternate dimension in which the Doctor's adventures existed as a fictional TV show called Doctor Who, a fan dressed as a Snowman of the Great Intelligence was present at a Doctor Who convention which the Eleventh Doctor visited with Ally in 2013. (COMIC: The Girl Who Loved Doctor Who)