Dragon Hunter's Takedown

Special Target—This spell costs {4} less to cast
if it targets a Dragon.
Tap up to X target non-Human creatures, where X
is the number of Humans you control. Creatures
tapped this way lose all abilities and get -10/-1 until
end of turn. If those creatures are Dragons, destroy
them instead. Their owner draws a card and loses 1
life for each Dragon destroyed this way.