Flipper

This 1964 series (based on the 1963 movie) was about a bottlenose dolphin who is adopted by (or adopts, depending on your point of view) the family of a Florida park ranger. Essentially Lassie with fins. It had a long run on Nickelodeon in the early 90's leading to increased popularity and a revival.

Flipper was revived both in 1995 as The New Adventures of Flipper, with a new cast of characters unrelated to the original (except for Keith, the grown-up version of Bud, in the first season) and in 1996 as a motion picture starring Paul Hogan and Elijah Wood, using the original TV show's characters.

One of the main trainers for the show now campaigns heavily against dolphin captivity after one of the dolphin stars died in his arms after the show ended.

One of the retired dolphin stars found a home in the east end zone of the Orange Bowl for the Miami Dolphins as a team mascott. The "Miami Dolphin" debuted in 1966.

Not to be confused with the Noise Rock band Flipper.

Tropes used in Flipper include:

California Doubling: Averted on the original TV show, which was set and filmed in Florida. Mostly played straight in the '90s version, which (apart from the pilot and two early episodes) was shot in Australia.
Catch Phrase: In season two of the '90s version rarely did an episode go by without at least one cast member going "I love that dolphin!"
- To the extent that the season two finale, the Clip Show "Reflections," ended with a montage of characters saying "I love that dolphin!" before Maya (Jessica Alba, in her last episode) finally got to say it.
Driven to Suicide: One of the dolphins.
Expository Theme Tune: On the '60s version (the '90s version had two different instrumental ones).
Friendly Playful Dolphin: Flipper is a playful, friendly dolphin, apart from being helpful.
Heroic Dolphin: Flipper might be the Trope Codifier as far as recent western media go.
Noisy Nature - Of the misplaced cry variety: Flipper's famous chatter is a kookaburra.
Non-Human Sidekick
Retool: Happened to the '90s version twice. The second season dropped the entire cast of the first season, except for Jessica Marie Alba (as she was billed in the first season), and reworked the premise to revolve around search and rescue people with Flipper working for them as a kind of rescue dolphin, essentially turning it into a Cop Show IN THE OCEAN! In the third season, Jessica Alba left and the second-season protagonist married someone who had never appeared on the show before, adding her two cute children to the cast. Thus, the premise became The Brady Bunch WITH A DOLPHIN! for the remaining two seasons.
Timmy in a Well