In short, the history of ASCII art started with the old telefax machines which could only send standaard text-characters but people wanted to see pictures too. So they figured out how to create pictures with text-characters. I proudly present my collection of ASCII-cows...moo! If you have some which are not listed yet, please send them to me.
A few examples
(__) (oo) U /-------\/ /---V / | || * |--| . * ||----|| ^^ ^^ Cow at 1 meter. Cow at 100 meters. Cow at 10,000 meters.