Well not strictly legless, but missing feet.
Jerry Moore has pointed out that when he was photographing the Sabine's Gull yesterday he noticed that the bird was missing a foot. Coincidentally Martin and I discussed this yesterday as we were seawatching. Apparently its not that unusual to find birds, particularly seabirds, that have lost feet. Causes include being entwined in fishing line, malformation or predators. I seem to remember reading years ago of birds resting on the sea being attacked by predatory fish.
Anyway, here it is------photographed by Jerry Moore.