Pilkey, Dav <br/><br/>
Captain underpants / 
Dav Pilkey 
 - New York :  Scholastic,   2012 
 - 94 pages. 
<br/><br/> This book explains how Tippy Tinkletrousers arrived at the end of the eighth book, as well as a prequel story of George and Harold in kindergarten explaining how their friendship began and setting the page for their life before Captain Underpants. 
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<br/><br/><label>ISBN: </label>9780545724227