This
gull was at East Beach, Galveston, Texas on November 16, 2005; clearly a LBBG-type, yet to my eye it looked rather odd:
Note below the extremely short tail:
Note the somewhat pale inner webs to the inner primaries, and the pale lesser secondary coverts on the leading part on the inner wing; LBBG has these coverts darker - similar to the primary coverts
The underwing coverts are "medium" rather than dark, being strongly mottled with pale marks. Also note the that retrices 6, 5, and 4 have solid white bases with no barring