Sparty's costume is made by Olympus Flag & Banner - that's according to this invoice that breaks down some of the different costs involving the costume.
Olympus Flag & Banner, where the payment has been made payable to is located at this address: 9000 W Heather Ave, Milwaukee, WI 53224; Phone: (414) 355-2010.
Olympus Group, a worldwide leader in the production of custom printed flags, banners, signage, and point of purchase materials, has an official website at www.olympusgrp.com.
For information on their products, or to request a quote, call them at 1-800-558-9620.
See their Facebook and Twitter pages for news and updates.
As for the company that designed Sparty, it's Real Characters, Inc., located at this address: 209-A Swanton Way Suite 201-C Decatur, Georgia 30030; Phone: 404-378-8801.
Real Characters' website is at www.realcharactersinc.com.