TODAY | July 20, 2013
>>> now, a story about a lame duck, literally. a duck was born with an inverted foot that prevented him from walking until now. dave has the story of butter cup's big comeback.
>> this is butter cup.
>> reporter: butter cup was born last november with his left foot inverted. he couldn't walk. but the lame duck was soon adopted by feather angels waterfowl agency in tennessee. they arranged for butter cup to have surgery to remove his bad foot.
>> he's a cheerful duck, happy all the time even with one little foot .
>> reporter: he had a hard time getting around. mike gary from the sanctuary had an idea.
>> i wanted to create a foot. i did design on paper and the computer and tried to simulate what would happen and what might he do.
>> reporter: the design went to copy in nashville. they used a 3-d printer to make a mold of the foot for free.
>> today is a big day for butter cup. he gets his new foot today.
>> reporter: a big moment, his first step. butter cup's fame got him an invitation to join the famous marching ducks in memphis to waddle down the red carpet on wednesday. this special duck has a lot to quack about.