Robert Ripley, the creator of Ripley's Believe it or Not!, had a thing for documenting macromutations, both in humans and in animals.
Most biologists believe that adaptation occurs through the accumulation of small mutations. However, some argue that macromutations (ie large-scale mutations) are responsible. This theory has generally been disregarded as the major explanation for adaptation, since a mutation on this scale is regarded as more likely to be detrimental than beneficial (eg. a frog with eyes on the inside of its mouth).
I visited Ripley's museum in Niagara Falls recently, and I got to see firsthand some of these oddities. I took some photos as I ventured through the facility (which, from the outside, resembles a fallen Empire State Building, including a defiant King Kong up top):
And here are a couple of fakes: