Keeping tabs on continuity on a film set is a nightmare. Props go missing and reappear multiple times during a scene. A piece of food might shrink and regenerate. I have always suspected characters drink from glasses without ice to maintain consistency throughout takes and cut down on condensation. Some films make great strides to keep things looking legit on set. For example, during the filming of Casino, Robert DeNiro would hold the lit end of his cigarette the same distance from his fingers regardless of how short it got during his numerous smoking scenes.
The prop master/animal wrangler on the set of Creed 2 gets a prize for including the original turtles, Cuff and Link, from Sylvester Stallone's breakout roll Rocky in the latest iteration of the boxing franchise. In a recent Instagram post, Stallone is pictured on the set of Creed 2 with his 44 year old amphibious friends. According to an article on TV Overmind the turtles have been in the possession of Joseph Marks, the original owner of the pet shop in Rocky, and subsequently his nephew, John Stuart.
Sure actors have starred in rolls that have spanned years, but it's incredible to think that those same turtles from the original film have made their way back into a sequel decades later. Seeing as these particulars turtles can live for much longer they might even outlast the Italian Stallion himself!