Long before Tom Holland or Tobey Maguire suited up as Spider-Man on the big screen, Marvel brought the web-slinger to Japanese TV through a licensing deal with Toei. The series lasted for 42 episodes and a movie and largely abandoned the source material for an extraterrestrial to appeal to Japanese audiences.

When Garia, an ancient wizard from the Planet Spider saves motorcycle racer Takuya Yamashiro's life with a blood transfusion, Takuya is transformed into the Spider-Man of Earth-51778. Before turning into a spider, Garia gives Takuya a spider-themed arsenal and passes on his 400 year-old vendetta against Professor Monster and his Iron Cross Army, the aliens responsible for slaying Takuya's father.

The most impressive took in this Spider-Man's arsenal is Leopardon, a giant mecha designed by mechanical designer Katsushi Murakami abandoned the source material, instead giving Spider-Man an extraterrestrial origin and a mecha: Leopardon

WHAT IS SPIDER-MAN'S LEOPARDON?

When "The Emissary of Hell" needs extra firepower, Takuya Yamashiro uses his Spider Bracelet to summon The Spider-Machine GP-7, a sweet flying car that is typically used to run over henchmen.

When Spider-Machine's missiles inevitably fail (and they always fail) against the monsters of Professor Monster, Spider-Man docks into the spaceship Marveller. With a hearty cry of "Marveller! Change Leopardon!" the spaceship turns into one of the most powerful weapons in the whole of the Marvel Multiverse: Leopardon!

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Like any good mecha, Leopardon sports a voice-activated arsenal. Leopardon has standard-issue Gigantor-like rocket arms, an obligatory arachnid tow cable called Spider String, a useless tiara-throwing move known as Arc Turn, eye lasers that turn everything yellow and Spider Protector, an energy web-shield.

Then there's Sword Vigor, which one of the most powerful attacks in any of Marvel's realities. Crossing his arms, Spider-Man screams "Sword Vigor!" prompting Leopardon to draw an energy sword from his scabbard. Leopardon throws the sword, inevitably one-shot killing kaiju without fail, especially Prime Minister Monster during the series finale from 2018's Vault of Spiders #1 by Sheldon Vella and Jed Mackay.

LEOPARDON, THE ORIGINAL MEGAZORD

If you've seen an episode of Mighty Morphin' Power Rangers, then you already have a good idea of how Leopardon works. After a monster of the week grows from miniature into a human-sized threat. Spider-Man fights some bad guys and calls down the Spider Machine to run over some for good measure. After the monster grows to giant kaiju proportions,Spider-Man calls down Marveller to change into Leopardon to resolve the plot.

While Super Sentai -- the series that provided footage for Mighty Morphin' Power Rangers -- predates Spider-Man, Toei only introduced giant transforming mecha into Super Sentai after Leopardon was met with immense popularity.

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Essentially, Leopardon could be seen as the most direct precursor to the Power Rangers' Megazords. In fact, the stock footage of Marveller changing into Leopardon perfectly matches the original Megazord transformation sequence from Mighty Morphin' Power Rangers. 

Unfortunately, the Leopardon suit was stolen during the latter half of Spider-Man's production. Lacking the funds to create a new suit, the show's producers simply created new battles by splicing stock footage of Leopardon into scenes with new monsters.

LEOPARDON IN SPIDER-VERSE

During 2014's Spider-Verse, every Spider-Man, Spider-Woman and Spider-creature fights yhe Inheritors, a family of Victorian-garbed energy vampires who could've stepped out of Castlevania. When the Spiders' "safe zone" is breached by Inheritors, Marvel's main Spider-Man reveals that he has recruited Takuya and Leopardon.

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Like a literal deus ex machina, Leopardon charges in to give his Spider-Homies time to bug out, as the Inheritor leader Solus rips the mecha apart. Fortunately, Leopardon's remains are recovered by Spider-Man 2099 and the steam-powered Lady-Spider. Despite being disassembled, Leopardon fights on, keeping two Inheritors at bay with arm rockets and eye rays. Augmented with both steampunk and cyberpunk technology, Leopardon returns for the final battle.

LEOPARDON IN SPIDER-GEDDON

Leopardon Spider-Geddon

The Superior Spider-Man, who's a somewhat heroic Doctor Octopus, recruits Tekuya and Leopardon as a headquarters for 2018's Spider-Geddon. This time around, Otto convinces Takuya to just start every fight with Sword Vigor, because it works literally all the time. In fact, the Inheritor Daemos deliberately breaches Leopardon, acknowledging that Sword Vigor is "actually a threat to my kind."

Though disabled, Leopardon once again resolves the plot as Miles Morales uses the Enigma Force to wield the gargantuan Sword Vigor, obliterating Solus. Though impressed, Takuya has just one note for Miles: "You're supposed to cross your arms when you say it."