Designated Hero: In the original film, despite causing the deaths of thousands of people, little Toshio repeatedly insists that Gamera is a "good turtle." The screenplay seems to be sympathetic to this view.
Ho Yay: Asagi had vibes of Les Yay with Nagamine near the end of Gamera 3.
Homegrown Hero: The Showa-era films have token American children shoehorned into stories set in Japan. Daiei did this specifically because their film distributor assured them the movies would be better-received in the US if there were Americans in the cast.
It Was His Sled: Gamera can fly. The original film actually had this power come as a surprise with him not displaying it till he's flipped on his back, but now it's as well known as his power to breath fire.
Older Than They Think: Most of the "Sandy Frank" dubs are actually Hong Kong Dubs produced around the 60s as means of pitching an English version overseas. Sandy Frank bought them and slapped his name on them when he marketed the films on VHS. The only ones he did dub were Gamera and Zigra.
The Scrappy: The children in the films are hated by many, especially Toshiro from the original due to his unintentionally disturbing obsession with Gamera, cheering whenever Gamera escapes the military's traps and convinced that Gamera is good despite him killing millions.
Ironically, most of the kids in later films aren't that obsessed with Gamera, except for Helen in Gamera vs. Zigra, who has a crush on Gamera.
In Gamera vs. Barugon,Gamera stabs Barugon in the face with his claws, causing gallons of purple blood to gush out and get all over the place.
Gyaos gushing blood out of his ears in the climax of Gamera vs. Gyaos.
The "Boss Viras" decapitating his humanoid henchmen in Gamera vs. Viras.
Space Gyaos gets sliced 'n' diced by Guiron in Gamera vs. Guiron. Also, Gamera removing Guiron's shurikens underwater, the process giving him untold agony!
In Gamera vs. Jiger, Gamera getts impaled through his arms and legs by long spears, , which make pulling the limbs back into the shell an impossiblity. He is able to pull the spears out of his legs, but not without grimacing and roars of pain.
Gamera ramming the idol into Jiger's skull.
The Heisei trilogy contains examples of:
Alternative Character Interpretation: Some members of the fandom tend to believe that Iris was supposed to be a guardian along side of Gamera but Ayana's rage and hate drove him to kill those she didn't like and ultimately go after Gamera. Others believe he was evil all along and was only using Ayana to get more powerful. Still others believe he was a 'failsafe' made to take out Gamera should he turn on mankind like the Gyaos did and Gamera's disreguard for mankind awakened him. Given how little of his origin is actually revealed, any of the three could be right.
Or all three, for that matter.
Also, was his showing Ayana the stuff he did taunting her out of evil intent? Or was he just showing his "mother" what he'd done for her?
Juliana Schano's "Tell Me Once Again" deserves special mention.
"Gyaos Flies Over" from the first film.
"The Myth" from the first film.
Fanon: Some fans believe that the Dragon and Tiger guardian, brought up in Gamera 3, that the former could be Barugon and Jiger, albeit some resigns would be needed, especially since both are reptiles and tigers are mammals.
In a What Could Have Been moment, a Gamera manga in Japan features the titular monster fighting against an updated, Heisei version of Barugon called "Balgon." (likely translation error) And what is this beast's origin? The young child of the former Dragon Guardian of the east, driven mad by lack of guidance from his mother or a bonded human. Also, Barugon was briefly considered to be the antagonistic monster in the first Heisei film.
Harsher in Hindsight: The legion flower blossoming by turning into a Fantastic Nuke (And temporarily killing Gamera) is pretty drastic in itself. What makes it even worse? The city it blows up is Sendai. Umm......
Hilarious in Hindsight: Gamera's Mana beam is one when you realize it's basically a Kamehame Hadouken. In Dragon Ball not only was Master Roshi a trainer of Turtle-Style Martial arts, but also rode a baby Gamera, and the Kamehameha can be translated as "Turtle Destruction Wave". Even better, it's a combined energy attack using the power of the planet akin to Goku's Spirit Bomb.
Surprisingly Improved New Series: Almost unanimously regarded as superior to the the Showa series, and made Gamera his own distinct character with more to separate him from Godzilla.
Speaking of What Could Have Been, there was a Godzilla vs. Gamera theatre play in the 70's using the suits of the respective series. In 2002 there was a planned Godzilla/Gamera movie crossover. Imagine if they were basically the Kaiju Avengers.
Ugly Cute: Iris' younger form is sometimes seen as this.
Wangst: Gamera accidentally killed Ayana's parents, so now she wants him dead. Fair enough right? What did he do, walk through her house? Throw Gyaos into it? Obliterate it with a stray fireball? No, actually, he landed on top of it while plummeting miles to the ground after possibly suffering brain damage from a head-shot from Gyaos' main weapon. BASTARD!
If her dreams are accurate, he walked through her apartment building after plummeting to the ground. Whatever the case, her not holding a grudge against him would be very odd!
He landed on top of it, and the action of getting up and taking off caused further damage. There was really nothing he could've done.
What an Idiot!: The military for most of the third film. Lets see, Gamera, in the process of killing Gyaos who have been confirmed to be capable of destroying an entire civilization that's more advanced than humanity, causes a good deal of damage to the city. The military instantly turn on him, not considering the possibility the Gyaos may be the bigger threat. Then, when Gamera is fighting Iris, the military decide to concentrate on killing Gamera...who has never been an active threat to humanity and is presently locked in combat with a known maneater. At least the finally get it together at the end of the film, but still, had they just let Gamera kill Iris instead of slowing him down and letting Iris make landfall, a lot of death and destruction would've been avoided.