You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.
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Question: Category: THE NATIONAL TOY HALL OF FAME 
Clue: Initial sales for it were sluggish, but demonstrations of how it walked down stairs at Gimbels made it walk off shelves

Answer: a slinky


Question: Category: THE ELEMENTS 
Clue: Most fluorescent lights are filled with a combination of argon & this element, Kr

Answer: krypton


Question: Category: TV ANIMALS 
Clue: He was 1st of several chimps featured in the early days of "The Today Show"

Answer:
j. fred muggs