Thanks for saving the animals. Illustrations were great touch and added so much needed whimsy to usually boring error pages. Another improvement that is a must - removable "Add-ons" button. I understand why "Menu" button is not allowed to be removed (although, it would be neat experiment to move it around toolbar), but "Add-ons" is just taking up space. And considering, that other browsers allow to hide their variant of "Add-ons" button, there should be no excuses for Firefox. Customization is a rare feature in browsers these days, and huge pro considering other browsers.