I have been using Linux for many years, but only recently found out about /etc/motd. When you SSH into a server, it displays a message that varies depending on your Linux distribution. For instance, a stock Debian installation looks like this:

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Wed Sep 14 23:38:34 2016
user@hostname:~#

I never thought to look at where this message comes from, but apparently it lives in /etc/motd. I believe this stands for “message of the day”. This means that you can have this message say anything that you would like by editing the contents of /etc/motd. For example, you can use this Text to ASCII generator to put the hostname of your server in stunning ASCII text and make it look like this:

Levs-MacBook-Pro:~ levlaz$  ssh dev.levops.net
     _            _                                        _
  __| | _____   _| | _____   _____  _ __  ___   _ __   ___| |_
 / _` |/ _ \ \ / / |/ _ \ \ / / _ \| '_ \/ __| | '_ \ / _ \ __|
| (_| |  __/\ V /| |  __/\ V / (_) | |_) \__ \_| | | |  __/ |_
 \__,_|\___| \_(_)_|\___| \_/ \___/| .__/|___(_)_| |_|\___|\__|
                                   |_|

dev:~#

This is pretty neat! You can also do some fancy things like Ubuntu does and make this message change depending on various events such as security updates being available or a server restart being required. You can explore the scripts that Ubuntu uses in the /etc/update-motd.d/directory on a standard install.