Ross: He's like a potato. A baked potato. A talking baked potato.
The Doctor: Now, Ross, don't be rude. You look like a pink weasel to him.
And occurred to me how completely different DW fanfiction would be today if only the Doctor had said that in "New Earth":
Rose: They're cats.
The Doctor: Now, don't stare. Look what you look like to them, all... pink weasel.