His body was the one in the morgue in Dead Beat that the necromancer Grevane was seeking and wanted to abduct Butters for. Apparently his body has some vital information on that the Necromancer wants badly enough to go around killing.(reference needed)
Tony is known as a "ballooner". As a youth, he was a sword swallower in a carnival. He would fill up ballons with jewels or drugs or other small items he wanted to move around. Then he'd tie the balloon with a string, swallow it, and tie the string to his teeth.(reference needed)
Dresden and Butters discover a balloon he had swallowed containing a jump drive. On it was a file folder with simply a string of numbers on it.
He is also the given reason that John Marcone later rescues Harry Dresden from the Corpsetaker and Li Xian and gives in the names of two EMTs that could help Dresden find Grevane and therefore Mendoza's killer. Marcone says: "Whoever murdered Mendoza must be Chastized immediately".