Cowsay – a configurable talking cow, written in Perl. It operates much as the figlet program does, and it written in the same spirit of silliness. cowsay is actually a pretty old program.
The first major version of cowsay had one cow and one message template: $foo is $verb $bar. Not very flexible, but people managed to do pretty interesting things with it.
The second major version scrapped many of the limitations of the first, by allowing arbitrary messages, multiple cowfiles, and even support for cows talking in figlet.
The third version was a rewrite of the second into Perl 5, whereupon the code got a lot smaller and more manageable.
The project developer is Tony Monroe.
Cowsay 3.03 source code 14KB.tar.gz