Anyone with time on their hands? An A380 is 238 feet long. Take a look at the video clock. Now time how long it takes from radome to tail cone passing any reference point. Chinagraph on your screen will do. I'd guess you'll come up with something well over 20 Knots/23 MPH if you prefer. No one in their right mind, JFK at night, would taxi an A380 at that speed - and nor did they.