Easter eggs in Ubuntu

PROBLEM:

I am bored with this website (all problems). Give me some fun!

Alright! Today I'll tell you somethings that might have not known about Ubuntu. You will be amazed how many Easter eggs are present in Ubuntu.

Get ready!

Here comes the first.

Open a terminal. Now type the following.

sudo apt-get install sl

Now type:

sl

You will see a train running in your terminal like this:

Now the second one. Type the following in your terminal:

apt-get moo

You will see a cow like this!

Now let's see the next one. 

So, apt-get has a cow. Does aptitude have one? Let's see

Open the terminal and type the following.

aptitude moo

You will see 

There are no Easter Eggs in this program.

What shall we do? Let's try again with:

aptitude -v moo

You will get:

There really are no Easter Eggs in this program.

And again:

aptitude -vv moo
aptitude -vvv moo
aptitude -vvvv moo
aptitude -vvvvv moo
aptitude -vvvvvv moo

The output will be like this:

Now let's try another.

Type the following :

telnet towel.blinkenlights.nl

What do you see command line star wars. Wonderful, isn't it.

Another one with firefox.

Press ALT + F2 and type the following:

firefox -url about:robots

firefox -url about:mozilla

I'll leave the output for yourself.

Let's see another one. This one is about incorrect passwords while using sudo command.

Type the following in a terminal:

sudo visudo

Now near the top, add a line :

Defaults insults

Save and close the file.

Now close the terminal and open another terminal.

Now use a command with sudo like:

sudo ls

Now type an incorrect password and see what it says.