Pollywogs!

http://www.neatorama.com/2006/08/21/six-horrifying-parasites/

I think the link says it all…

SNAIL MIND CONTROL!!!
http://www.youtube.com/watch?v=EWB_COSUXMw

LEG WORMS!!!
http://www.youtube.com/watch?v=Hm13imVTYMA&NR

HUMAN MIND CONTROL!!!!!11111!!!11
http://microbiologybytes.wordpress.com/2006/08/04/dominated-by-men/