Found this watching a video about sudo. Add the following to your sudoers file to get insulted every time you fail to enter the password correctly, e.g.
[sudo] password for nate: stty: unknown mode: doofus [sudo] password for nate: That is no basis for supreme executive power! [sudo] password for nate: This man, he doesn't know when he's beaten! He doesn't know when he's winning, either. He has no... sort of... sensory apparatus... [sudo] password for nate: Take a stress pill and think things over. [sudo] password for nate:
This is the default behaviour of sudo and it should insult you if you can’t type your password but most distros have it disabled, completely pointless but good fun. To add it use
sudo visudo # then add Defaults insults
Make sure to finish it with a blank line.