get a random cow for use in `cowsay -f cow $msg`

get_cow.py

#!/usr/bin/env python
import subprocess
from random import randint

COWSAY = "/usr/games/cowsay"

def get_randomth(arr):
    return arr[randint(0, len(arr) - 1)]

def get_critters(cowsay):
    (critters, err) = subprocess.Popen([cowsay, '-l'], stdout=subprocess.PIPE).communicate()
    if critters:
        animal_lines = critters.split('\n')[1:-1] # edges of stdout are garbage
        return [animal for animals in animal_lines for animal in animals.split(' ')]

if __name__ == "__main__":
    available_critters = get_critters(COWSAY)
    print get_randomth(available_critters)

# corutils version:
# echo `/usr/games/cowsay -l | awk 'NR>1{ print $0 }' | xargs shuf -e | head -n 1`