In "Dolphin Tale," the role of Winter, the dolphin with the prosthetic tail fin, is played by the real-life Winter. The film ends with documentary footage of Winter with her current handlers, and she's doing pretty well for herself. She's got a good life. (Probably a better life than you.) When "Free Willy," the obvious spiritual forefather of "Dolphin Tale," came out 18 years ago, the "actor" Keiko was not so fortunate.
It's bizarre to think, in the world we currently live in, the animal star of a film actually needing assistance because of poor living conditions, but that's what happened with "Free Willy." The film itself was a moderate hit -- its lasting effect on pop culture is larger than anyone would have thought at the time -- but it really took off because of a letter campaign to Save Keiko. Willy had a better life thank Keiko; Keiko needed freeing far more.
There's still a Keiko.com Website detailing most of the timeline, but here's the short version. Reino Aventura, an amusement park in Mexico City, bought Keiko in 1985 but lacked the funds to be able to care for him properly. Plus: Whales probably shouldn't be in tanks; they should be in the ocean. Meanwhile, Warner Bros., in need of a cheap place to film a movie about a whale, rented out the park and Keiko to make their film. The film comes out, is a surprise "hit" and, next thing you know, children worldwide are telling their parents to call Warner Bros and make them put the whale out to sea. Eventually, they succeeded, but it is worth remembering that Warner Bros. had no plans to save Keiko until its movie caught on ... and even then had to be pushed.
From that came a movement to save and protect whales that persists to this day, as well as three sequels and a cartoon series. The actor who played Willy's child buddy, Jason James Richter, is now 31 years old, plays in an indie rock band called Fermata and loves the Jacksonville Jaguars. Not the Dolphins.