Spiderman costumes usually come in one-piece designs with separate hoods and are polyester or cotton. Choose tight polyester for a look that is more authentic; if comfort is key, choose cotton. Cotton breathes better than polyester and is more comfortable, especially if you intend to wear it to a party or in an enclosed space. If you don't fill out the suit in quite the same way Peter Parker did, don't despair. Buy a Spiderman costume on eBay that has padding in all the right places to recreate the look of this comic book icon.