Snowman (The Snowman)

A snowman was the titular character in the television special, The Snowman.

When the Tenth Doctor said goodbye to Mason Valentin, he said, "After all the flying around, having fun, and doing the impossible I've reali[s]ed something: I'm the Snowman and...time's up." (PROSE: The Doctor on My Shoulder)

Behind the scenes
The Snowman featured in DWM 213's Doctor Who? instalment as a "real" individual. He teamed-up with an Ice Warrior, a union that was later considered "unfortunate", and walked through the air with him and James.