If you haven't seen the ultimate New Zealand scifi mutant horror flick Black Sheep, then you are missing out on what is finest in life. Genetic experimentation on a remote farm leads to weresheep!
In this scene, you can see what happens when sheep go bad and do things that are more destructive than farting (though admittedly they do a lot of farting in this movie too). Why does the sheep look so awesomely cheesetastic? Because the brainiac maniacs at Peter Jackson's Weta Workshop made that creature - the one with the bitey teeth and savage driving ways.
If you like gory, silly movies about why GMO sheep are bad - especially when they get a little human DNA in there - then Black Sheep is the flick for you. Plus it's true, homegrown New Zealand scifi of the very best kind. Where else would the fear of sheep run so deep that you got a scene like this one?