Without knowing precisely which distribution/version you were using, it's hard to determine how to do this, because they are quite a lot of options.
But usually, this either is done by the "login" program, or the shell you are using to work at the command line.
For example, login usually display the content of /etc/motd file, which could be updated regularly by a scheduled job.
Or you login shell could be doing this in its initialization (or .xxxxrc) file.
Usually, the provider of those funny quips is "fortune": make sure it is installed on you system, by invoking it at the command-line. It usually comes with a default fortune-cookies database that you can expand by installing more packages.
- you have fortune installed
- your login shell is bash (check by logging in and doing "echo $SHELL")
You can invoke it into your shell initialization script by adding those lines at the beginning of your ~/.bashrc
## The if below test:
# - wether we have a terminal attached and
# - whether this is a login shell
# because automatic process are usually not interested in fortune
# cookies: they might even cause bugs.
if [ -t 0 && "$SHLVL" == "1"]; then
Make sure to keep a copy of your old .bashrc, in case you make a mistake modifying it ;-)