Adrianne Lewis may well have the longest tongue in the world at four inches, and while she's still waiting to get the official record, she does have the ability to lick her own eyeball with it. No one can ever take that from her...
The oft-quoted weird tongue fact about the human body is that you can't lick your own elbow, but that's not a problem for Adrianne, whose gigantic tongue can even lick her own eyeball it's so long.
Adrianne's tongue has been measured at four inches, which would beat the current record of 3.97 held by Nick Stoeberl, but Guinness have rejected her application three times apparently, so she can't be crowned champion. She would certainly also hold the female record which is currently held by Chanel Tapper, whose tongue is listed at 3.8 inches.
She has a number of party tricks with the tongue, including the aforementioned eyeball touch (for which she needs to use her hand, but we'll give her a pass on that) and elbow licking, all of which confirms that yes, her tongue is ridiculously long.