Perhaps different kinds of dragons?  We can have some that are friendly with humans and aren't much of a threat but then some that are the gigantic things, majestic but incredibly dangerous and incredibly intelligent. 
Something this -
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[img]http://images5.fanpop.com/image/photos/28200000/Dragon-dragons-28270304-700-525.jpg[/img]
[/hider]versus something like this - 
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[img]http://41.media.tumblr.com/4f917ac2f72d13bfe7a871701c392047/tumblr_nnp5j8UxNm1tqfyozo1_500.jpg[/img]
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But not too many dragons.