Possible Clues:

• #1 sports mascot, per ''Forbes''
• Citi Field icon
• Citi Field instigator
• 2007 Mascot Hall of Fame inductee
• N.L. mascot whose head is a large baseball
• Mascot at Citi Field
• New York MLB mascot
• Mascot with a baseball head
• Symbol of Big Apple baseball
• Mascot whose weight is listed as 'Top Heavy'