Snapatar is an online tool which allows you to change/update your Twitter profile picture in two steps.
This tool is damn simple to use, all you need to do is open the page in browser, allow it to access your webcam, finally pose the way you want, and shoot a photo using the ‘Snap!’ button. Once done with this, enter your Twitter username and password, if you want you can send a Tweet as well telling people about this profile photo update, using the option below the password field.
Adjacent to ‘Snap!’ button you can get the timer button (a five seconds automatic shooting mode is enabled) and a button to flip the photo horizontally while shooting (mirror image).
So go ahead and change your Twitter Profile Picture, using Snapatar.