"The animal in the image appears to have five visible legs, but this is an illusion caused by the overlapping of legs and motion blur. Zebras, like all equids, only have four legs."

Not perfect, but also doesn't always regress to the usual answer.

"The animal in the image appears to be an elephant, but it has been digitally altered. It visually shows six legs, although the positioning and blending of shadows and feet are unnatural and inconsistent with real anatomy. This is a visual illusion or manipulation." (actually should say five)

"This bird image has also been manipulated. It shows the bird with three legs, which is anatomically impossible for real birds. Normal birds have exactly two legs." (correct)

"Each shoe in the image has four white stripes visible on the side." (correct)