How to Remove a Twibbon
Twibbons are small overlays that can be added to your Twitter avatar photo or image to display a cause or interest that you believe in, follow, or promote. A number of Twibbons have a "use-by" date, however, if they relate to a time-specific event. Or, you might simply want to rotate causes, or free up your avatar image again. This article explains how to remove the Twibbon.
You can sign in using your Twitter name if wished - the link is at the top right hand corner of the page.
This is where you will find the "Avatar History" retained since you joined Twibbon.
Select the one that you want to remove and click on "Hide this". The avatar image you have selected will be removed as your profile image.
Be patient if the avatar image does not revert on Twitter - it may be immediate, or it can take up to 24 hours for this change to come through.
Part 2Alternate method
You have the options to "Change Image" or "Delete Image". Choose whichever you prefer.
The Twibbon will have been removed because you have removed the avatar image that carried it. Upload either your original avatar or a new one, as wished.