What is a funny halloween costume for a mature 13 year old guy?

you should dress up as a girl! get a female friend to help you and yeah :]

as a girl!!! that would be so awsome put on some lipstick and buy those silicone bras and u will look awsome!!

Please look the idea halloween costume at Amazon. http://www.amazon.com/Costumes-Accessories-Specialty-Apparel/b/ref=amb_link_7469932_2?ie=UTF8&node=258061011&pf_rd_m=ATVPDKIKX0DER&pf_rd_s=top-2&pf_rd_r=0ZE4GRCHEF8X5ES4Q786&pf_rd_t=301&pf_rd_p=436521501&pf_rd_i=halloween%20costume&tag=best-buy-prices-20 Hope this help. Good Luck.

clown

Chick Magnet http://images.halloweenexpress.com/images/imagecache/48-125-gc6091.jpg Sugar Daddy http://images.halloweenexpress.com/images/imagecache/85-125-gc4012.jpg Homer http://images.halloweenexpress.com/images/imagecache/94-125-dg6697.jpg Bad Sport Cheerleader http://img.costumecraze.com/images/vendors/rubies/886033-thumb2.jpg Cartman http://img.costumecraze.com/images/vendors/disguise/6386-thumb2.jpg Hannah Montana http://img.costumecraze.com/images/vendors/disguise/6681-thumb2.jpg Satan from Southpark http://img.costumecraze.com/images/vendors/disguise/6388-thumb2.jpg Beetlejuice http://img.costumecraze.com/images/vendors/rubies/886127-thumb2.jpg

be a wrestler or a biker

the cow http://www.halloweencostumes4u.com/Merchant2/graphics/00000003/15225.jpg whoopie cushion http://www.partycity.com/cgi-bin/parties/costumes.cgi?thepartytype=&name=Whoopie%20Cushion&parties=Halloween&productstype=Boys&products=175163&zoom=1&start=&originaltype=Costumes sumo http://www.partycity.com/cgi-bin/parties/costumes.cgi?thepartytype=&name=Inflatable%20Sumo&parties=Halloween&productstype=Boys&products=175236&zoom=1&start=&originaltype=Costumes

maybe an animal

If you have to ask, you are not mature enough yet. Maturity comes from life's experiences and once you attain that you will know what a good costume will be based on what you want to project.