Tu

Tu was a bovine creature with a liking for womens' clothing and one of the aliens that lived on Maught who entered into a fragile "partnership’" with Blontt and Angelo – with each of the three having one of the necessary co-ordinates to drill down into a long lost underground stream. He obtained the north south co-ordinates (4.97 degrees), from a "guest" who took hospitality at his inn. By drilling too deep with false co-ordinates given by the Tenth Doctor, the underground stream was exposed and allowed water to flow across the planet's surface once more. (COMIC: The Green, the Bad and the Ugly)