How to get more than cows from cowsay

I have recently installed cowsay and am using it to amuse me by piping the output from fortune to it. And although this is great, I understand that you can get more than just cows with cowsay, and I have looked in /usr/share/cowsay/cows and found the following files:

apt.cow                ghostbusters.cow  sheep.cow
beavis.zen.cow         gnu.cow           skeleton.cow
bong.cow               head-in.cow       snowman.cow
bud-frogs.cow          hellokitty.cow    sodomized-sheep.cow
bunny.cow              kiss.cow          stegosaurus.cow
calvin.cow             kitty.cow         stimpy.cow
cheese.cow             koala.cow         suse.cow
cock.cow               kosh.cow          three-eyes.cow
cower.cow              luke-koala.cow    turkey.cow
daemon.cow             mech-and-cow.cow  turtle.cow
default.cow            meow.cow          tux.cow
dragon-and-cow.cow     milk.cow          unipony.cow
dragon.cow             moofasa.cow       unipony-smaller.cow
duck.cow               moose.cow         vader.cow
elephant.cow           mutilated.cow     vader-koala.cow
elephant-in-snake.cow  pony.cow          www.cow
eyes.cow               pony-smaller.cow
flaming-sheep.cow      ren.cow

Which all seem to be different cool things like this was the contents of ghostbusters.cow:

So my question is, how do I activate all these other fun creatures? And can I get it to pick one at random for each strange message?

Solution 1:

To achieve what you want run :

fortune | cowsay -f ghostbusters

And for random ... :

fortune | cowsay -f `ls /usr/share/cowsay/cows/ | shuf -n 1`