Why are weasels villains?

[Avengium]

http://tvtropes.org/pmwiki/pmwiki.php/Main/WickedWeasel Interesting.

http://www.orionsarm.com/eg-article/47f591591626f Putorians, Neputons, and Nanputons

If you search for "Neputans", the search function return: "No search results found".