ballhawk
n.— «The neighborhood around Wrigley Field, called Wrigleyville, is filled with fans on game day. Ballhawks, as they are called, wait on Waveland Avenue to catch home runs during the game.» —“Wrigley Field ivy turns 70″ by Tom Hintgen Daily Journal (Fergus Falls, Minnesota) May 7, 2007. (source: Double-Tongued Dictionary)