WARNING: this video contains lots of colorful ponies in just under one minute.
cponysay [1] is a C implementation of Ponysay [2], which is a "Pony rewrite of cowsay" and it has 541 ponies at this moment.
The build process is not short, because all 541 ponies have to be compiled, and if you have insomnia, try
$ i=0; for pony in $(./cponysay -l); do clear; ./cponysay -p $pony $((++i)) ponies; sleep 1; done
Either it works or you would get hypnotized by ponies, then you may ponysleepwalk, use at your own risk.
$$$
cponysay:
Ponysaying since 2016-09-09
git-fd77804879f8c418f19ec111b290d4f0368e5b31 (2016-10-31)
In C with Ponysay [2]
By Fredrik Hansson (FredrikHson)
GPLv3
Ponysay
git-4eddb7a48fca73c5eba2e28f9db70aa587002c95 (2016-08-30)
By Erkin Batu Altunbaş (erkin), et al.
GPLv3
[1] https://github.com/FredrikHson/cponysay
[2] https://github.com/erkin/ponysay