- In the 1990 film the "Cowabunga" catchphrase is introduced to the Ninja Turtles by Splinter.
- In the 2014 film it's revealed Raphael made Michelangelo promise never say it again, but Raphael allowed him to say it one last time, against the Shredder.
Coming Out of Their Shells
2012 TV series
- In the 2012 TV series it was replaced by a new catchphrase, Booyakasha for two and a half seasons. In Meet Mondo Gecko, Mondo Gecko introduced the phrase Cowabunga into the series. Ever since Meet Mondo Gecko, Michelangelo uses Cowabunga from time to time, although he still more often uses Booyakasha.
- A sports equipment store named Cowabunga appears in the background of various episodes.
- At the end of The Manhattan Project, Part 2, the 80's turtles charge against a Kraathatrogon shouting "Cowabunga".
- The new Party Wagon's license plate sais "CWABNGA" in previous artworks instead of LUVDCTR.
- "Cowabunga" is Mondo Gecko's catchphrase in the episode Meet Mondo Gecko.
- The phase is used in the game Teenage Mutant Ninja Turtles: Turtles in Time when the Turtles finish levels.
The phrase "Cowabunga" was actually not from TMNT to begin with. It actually came from the British ventriloquist show the Howdy Doody Show in the 1950s by the character Chief Thunderthud. Writer Eddie Kean wanted to think of a word that's the opposite of the friendly "Cowagoopa" which is "hello", instead of the usual "Hao". So, Eddie Kean came up with "Cowabunga", showing a sign that the character, Chief Thunderthud, would get frustrated.
Eventually, after the Howdy Doody show was off the air, the word got stuck into people's minds, over the years it has become a kind of triumph for surfers, eventually getting into different media like the Ninja Turtles; and since Michelangelo is known for "pop culture references", it doesn't hurt that Cowabunga, would be used. This phrase enjoys some successor, mostly as a spoof of of clichés.