By peoplestaff225
Updated December 01, 2008 07:30 PM

Robert Clarence Irwin celebrates his fifth birthday with mum Terri and sister Bindi Sue, 10, during a party at Australia Zoo on Monday on the Sunshine Coast, Australia.

"Crocodile Hunter" dad Steve Irwin passed away in September 2006, after accidentally being pierced by a stingray’s barb.