The file ~/.bashrc allows you to make the customizations you would like, among other things.

First open it with gedit ~/.bashrc

Now in order to have the multicolored prompt, find the line that looks like this:

#force_color_prompt=yes

Un-comment it (remove the #).

Now to get the ascii art and quote, you will need to install two packages:

sudo apt-get install cowsay fortune

Now in ~/.bashrc add a line with:

fortune | cowsay

Save the file, and restart your terminal (or resource the file with source ~/.bashrc).