While there are plenty of characters in the world of basketball, Dikembe Mutombo was larger than life both on and off the court. On Tuesday night, the Atlanta Hawks paid tribute to the star center by retiring his number 55 jersey before their game against the Boston Celtics. “Atlanta, I love you guys,” Mutombo said during the ceremony. “I thank you so much.” The Congo native was known for his defensive ability during his playing days. Using his 7'2" frame and seemingly-endless arms, he finished his career with the second most blocks in NBA history; he also became known for wagging his finger at the shooter after he swatted the ball away. Of the court, Mutombo has spent countless hours on humanitarian work. In 1997, he founded the Dikembe Mutombo foundation in order to improve living conditions in his home country by building hospitals and spreading information about diseases like polio; he is also a strong supporter of the Special Olympics and the international relief agency CARE. Following the ceremony, the current Hawks put together a strong performance as they defeated the Boston Celtics 121-97. Paul Millsap and Jeff Teague combined for 41 points and, fittingly for the evening, the team blocked seven shots. Photo: Basketball player Dikembe Mutombo attends the RFK Ripple Of Hope Gala at Hilton Hotel Midtown on December 16, 2014 in New York City. (Photo by Mike Coppola/Getty Images for RFK Ripple Of Hope)