Roman Games: Playing with Animals – The Metropolitan Museum of Art https://www.metmuseum.org/essays/roman-games-playing-with-animals
Since the acquisition of exotic creatures was very expensive, they would often be sent to menageries or zoological gardens around Rome to be tamed and trained for public entertainment before they reached the games, where death was inevitable.
Los Angeles: Getty Museum, 2001. Grant, Michael. Gladiators. Rev. ed.