Gris

Gris was a planetoid which the Tenth Doctor visited billions of years BC. The smell from the nymph glands were stuck on his suit, allowing Mamps Slitheen to identify him as a time traveller when she met him in 1500 BC. (PROSE: The Slitheen Excursion)

It was mentioned by the Ninth Doctor as one of the "thousand worlds out there", whose skies were filled with dioxins, that the Nestene Consciousness could colonise without harming anyone. (PROSE: Rose)