DYKWIA n. an abbreviation of “do you know who I am?” said to be used by celebrities or others seeking special privileges. Also attrib. (source: Double-Tongued Dictionary)
Further reading
In 1916, a small-town newspaper in Pennsylvania printed a fanciful item about a local gathering with a guest list that included, among others, Miss Ella Vader, Mr. Ray Zor, and other punny names. This is part of a complete episode. Transcript of...
You might describe someone particularly talkative or gossipy by saying that their tongue wags at both ends. A more elaborate version is Your tongue wags at both ends and is tied in the middle. Another variant: Your tongue is hinged in the middle...