Here are some deleted scenes from your favorite kaiju films!
Frankenstein Conquers The World
Destroy All Monsters
Godzilla vs. Biollante
Godzilla vs. MechaGodzilla II
Godzilla vs. SpaceGodzilla
Godzilla vs. Destroyah
Godzilla: Final Wars

Frankenstein Conquers the World
Frankenstein vs. Oodako

At the end of the battle between Frankenstein and Baragon in the film "Frankenstein Conquers the World", Frankenstein breaks Baragons neck and the quadruped kaiju’s body goes limp. Frankenstein, bellowing in victory, drops Baragon’s body to the ground as the Earth beneath him gives way, swallowing up both kaiju. However, this film had a different ending, which the Japanese eventually cut from the final film. In this deleted ending, after Frankenstein breaks Baragon’s neck, he picks up the body and tosses it into a ravine, all the while roaring in victory. Frankenstein then turns to escape the burning forest, only to find the giant octopus Oodako slithering towards him from a nearby mountain. Seeing this, Frankenstein instantly attacks the giant octopus, but Oodako catches the giant human in his tentacles. Frankenstein battles back, actually managing to free himself and flip over the giant octopus. Oodako quickly recovers, however, and grabs Frankenstein once again and begins to drag him toward the ocean. Frankenstein fought with all his might, but when Oodako fell off a cliff, there was nothing he could do and both kaiju tumbled into the ocean. Frankenstein emerged from the water several times for air, but he could not escape the giant octopus in its natural element and Oodako eventually pulled Frankenstein under for the last time.

Destroy All Monsters
Godzilla vs. Manda

When the Kilaaks finally attacked Tokyo in the film "Destroy All Monsters", they sent in four kaiju to completely wipe the city from the face of the Earth. Godzilla, Rodan, Mothra, and Manda tore their way through the city in a matter of hours, obeying the Kilaaks every command until the Japanese capital was nothing more than a pile of smoldering rubble. However, there was one scene that was cut out of this spectacular rampage, mainly due to the insistence of director Ishiro Honda and SFX director Arikawa. While destroying Tokyo, Godzilla and Manda come across each other and a brief battle ensues. Manda hissed at the Monster King as he came to close to the giant serpent, who was coiling around a skyscraper. Godzilla didn’t take to kindly to this aggression toward him and bellowed a challenge to Manda as he advanced on the God of Mu. Godzilla then grabbed Manda and tried to pry him from the skyscraper, which collapsed to the ground as Manda was pulled off. Trying to escape, Manda hissed and wiggled around wildly, trying to escape Godzilla’s grasp. This goes on for a few moments, but then the monsters suddenly end their scuffle, the Kilaak mind control apparently telling them to stop fighting each other and return to destroying Tokyo, which they did. I would have to agree with both directors on the decision to have this scene cut. The Kilaaks were supposed to have total control over all Earth's Monsters, I think having this short battle between Godzilla and Manda would have made the alien threat seem weaker than it actually was. That, plus Godzilla doing battle with a suit-on-a-cord monster just looks odd, too bad they didn't have the great CGI that we have today.

Godzilla vs. Biollante
Flowers of Biollante

Near the end of Godzilla and Biollante’s first battle in the film "Godzilla vs. Biollante", Godzilla sets Biollante’s rose form on fire with his radioactive heat ray, totally engulfing the plant monster in flames. Godzilla stands, watching his burning foe until she is reduced to nothing more than a golden cloud of energy spores. In the finished film, these spores simply lift up into the sky and later return as the final form of Biollante to battle Godzilla once again. However, in a cut scene from the film, the spores disappear into the sky, but some also settle on the ground around where the battle with Godzilla took place. The area around the battle then begins to blossom as thousands of colorful flowers bloom, completely covering the ground. Godzilla sees this and seems curious for a moment, but then simply turns and heads back out to sea. Special Effects director Koichi Kawakita was very impressed with his work on this scene, but the scene had to be removed. The reason was because although the flowers were beautiful, they were out-of-scale and appeared to be gigantic in the film.

Godzilla vs. MechaGodzilla II
Life vs. Artificial Life

There are so many cut scenes in this film that I can’t even make a classy story out of it like the other deleted scenes! Anyway, at the end of the film “Godzilla vs. MechaGodzilla II”, MechaGodzilla has killed Fire Rodan after he severally damaged Garuda, knocking the flying machine out of the sky. However, Godzilla arrives and engages in battle with MechaGodzilla, who is eventually able to destroy the Monster King’s spinal brain with his “G-Crusher” weapon. Down for the count, Godzilla’s body lies motionless in the streets as MechaGodzilla blasts away at his body with all of his weapons. However, the nuclear reactor onboard Garuda suddenly ruptures and explodes, showering the area with radiation and resurrecting Godzilla. His spinal brain now regenerated and his body flooded with new radioactive energy, Godzilla rises and proceeds to completely destroy MechaGodzilla before returning to the ocean with Baby Godzilla. Now although this ending seems better suited to Godzilla's long-standing nuclear-based origin, Toho felt that Fire Rodan's self-sacrifice was more in keeping with the theme of Life against Artificial Life. Along with this different ending, there were at least five other cut scenes in this film. One scene was on Adona Island when the team of scientists uncovered Baby Godzilla’s egg, they were attacked by a pair of pteranodons and could not get off the island. MechaGodzilla was called in and the robotic kaiju made short work of the flying dinosaurs, killing one of them and knocking the other into the ocean where it was exposed to radiation from the nuclear waste site and turned into Fire Rodan. After this idea was rejected and the battle between Godzilla and Fire Rodan on the island decided upon, the idea of having a short scene from Godzilla’s past where he, as a Godzillasaurus, battled a pteranodon (Fire Rodan), but this idea was also dropped. Another interesting idea in this film was to have MechaGodzilla be able to separate into two different robotic vehicles, but although the idea wasn’t used in this film, it would later be used for MOGERA in Godzilla vs. SpaceGodzilla. In yet another rejected idea, the original ending of the film had Godzilla picking up Baby Godzilla in his teeth, kind of like a mother crocodilian would, and heading out to sea instead of them both swimming away, Baby Godzilla trailing behind Godzilla. However, it was though that the scene wouldn't be very convincing because Godzilla was so much larger than Baby Godzilla, so it was dropped. Finally, in the last rejected idea that I know of, the director of the film, Takao Okawara, also wanted to kill Godzilla in this film, because he felt that what makes Godzilla (1954) so powerful is the fact that Godzilla is killed at the end of the film. However, Toho would not allow that at this time and through out his idea.

Godzilla vs. SpaceGodzilla
Rescue Attempt

Toward the end of SpaceGodzilla’s attack on Godzilla and Little Godzilla on Birth Island, the evil space kaiju had all but defeated the Monster King with his cosmic powers. Trying with all his might to protect his adopted son, Godzilla could not prevail against his space clone and was finally brought down by SpaceGodzilla. Then, seeking to wreak more havoc on Godzilla’s mind as well as his body, SpaceGodzilla lifted Little Godzilla into the air with his gravity tornado and placed him within one of his crystal deposits, the giant crystals closing around the young kaiju, trapping him. Then with a roar of triumph, SpaceGodzilla took to the air and headed for Japan, leaving Birth Island alone. Moments pass, but finally Godzilla rises to his feet, injured, but his regenerative powers have healed him almost completely. Godzilla looks around and calls out for his adopted son, who cries back from within his crystal prison. Godzilla moves in and tries to free Little Godzilla from the crystals, blasting them with his heat ray and tugging at them with all his might, but they won’t budge. Furious, Godzilla bellows in anger and heads for the ocean, where he submerges and heads off after SpaceGodzilla to seek revenge for both himself and Little Godzilla. It is not known why this scene was cut from the final film, but it would have better explained why Godzilla immediately heads for Japan to confront SpaceGodzilla after his Birth Island defeat.

Godzilla vs. Destroyah
Alternate Ending

It is pretty widely known that the 1995, "Godzilla vs. Destroyah" had an alternate ending. It's not exactly known why this ending was cut from the film, but in any case, here's how it went... After the final form of Destroyah kills Godzilla Junior and Godzilla fails to revive him, the Monster King moves in to confront Destroyah and take revenge. After battling back and forth for a while, Godzilla advances toward Destroyah and the crustacean kaiju’s chest opens and begins to flash. Seconds later, a powerful beam erupts from Destroyah’s chest and strikes Godzilla, knocking the King of the Monsters to the ground as large explosions rock the area. However, overcome with rage due to both the death of Junior and his out-of-control radioactivity, Godzilla is quickly back to his feet and blasts Destroyah with his super-charged radioactive heat ray several times. Destroyah falls and a huge cloud of micro-oxygen billows out from where he fell. Destroy soon rises once again, heavily damaged, and attacks Godzilla. Godzilla evades an attack by the crustacean kaiju, grabs his horn, and begins to slam Destroyah again and again with his fists. While Godzilla holds onto Destroyah, the JSDF launches freezer missiles at Destroyah while the Super X3 fires its freeze cannon. Soon the combination of Godzilla radioactivity and freeze weapons takes their toll on Destroyah and the crustacean kaiju goes down for the last time. With Destroyah dead, the JSDF turn their freezer missiles on Godzilla, but it is too late to save him and the King of the Monsters goes into meltdown, disintegrating into a puddle of radioactive flesh and polluting the air with radioactivity. As high levels of radiation hover over Tokyo, all is seemingly lost, but suddenly the radiation levels begin to fall rapidly and the mist clears, revealing a monstrous shape as a familiar roar echoes across the great city. Godzilla Junior has absorbed the radiation from Godzilla and revived, mutating into an adult Godzilla.

Godzilla: Final Wars
The Death of Anguirus, Rodan, and King Seesar

In Godzilla: Final Wars, Godzilla was supposed to destroy every single one of his opponents throughout the film. However, once the King of the Monsters battled and defeated the monsters Anguirus, Rodan, and King Seesar, he simply left them in a pile and with a triumphant roar, walked away. Godzilla was originally supposed to blast the pile of wounded kaiju with his radioactive heat ray, destroying them utterly. The four-way battle between Godzilla, Rodan, Anguirus, and King Seesar was actually one of the first scenes filmed for Final Wars and the death by heat ray conclusion was planned, but the crew didn't want to torch the suits since they would be needed in later scenes that had yet to be filmed. Also, there just wasn't enough time or resources to make two suits for Rodan, King Seesar, and Anguirus. So in the end, it’s pretty much left up to the fans to decide whether or not Godzilla let the three kaiju live or destroyed them.