Pokémon

The anime series known as Pokémon has made references to the Godzilla Franchise since it first began.

Generation I References
The very first Pokémon generation featured the popular games Red, Green, Blue and Yellow, yet there have been abundant references to the Daikaiju franchises.

In the Show

 * In one episode of the Pokémon anime, a giant Caterpie attacks a city similar to Tokyo. The Caterpie evolves into Metapod, and eventually evolves into Butterfree. This entire sequence was very similar to Mothra's very first movie appearance.
 * In an episode that was later banned in America in the wake of 9/11 (but later un-banned when the show was picked up Cartoon Network), a group of Tentacool's attack a city followed by a Giant Tentacruel attack similar to the way Daikaiju destroy cities.
 * In an episode of Pokémon, the main characters go searching for fossils and they resurrect an Aerodactyl. Aerodactyl is a pterodactyl-based Pokémon. Aerodactyl starts to terrorize the group through Hyper Beam. This entire process is very similar to Rodan's appearances and depictions.

The Pokémon

 * The Pokémon evo-family Caterpie, Metapod and Butterfree have made references to the Godzilla Monster Mothra. They both are flying insects, weak to fire, use winds and powder/beams as weapon and are usually predicted as female.
 * The Pokémon evo-family Nidoran (Male and Female), Nidorina, Nidorino, Nidoking and Nidoqueen have similar appearances/behaviors as Baragon. Nidoking has a large horn erecting from his head that can be used as a weapon which is remarkably similar to Baragon. Baragon and Nidoking also share the ability to burrow.
 * The Pokémon Gyarados in the Pokédex states that it if provoked it will come from the sea and destroy cities and towns. This is very similar to Godzilla who attacks Japan whenever angered. On another note, Gyarados looks similar to Manda.

Generation II References
The second generation of Pokémon has less references than the first generation but there are a few.

In the Movies

 * In the movie "Pokémon Heroes", an Aerodactyl is summoned to destroy the city and its citizens. This again was very similar to Rodan and other monsters.

The Pokémon

 * The Pokémon Feraligatr's design is very similar to that of Zilla. This similar appearance is closer with Feraligatr's shiny coloration which has colors similar to Zilla with blue dorsal fins and a teal color. Even though the Gold and Silver versions of Pokémon were revealed in 1997 by Nintendo and they were released in 1999 in Japan, Feraligatr was not revealed any time before June of 1998.
 * The Pokémon evo-family Larvitar, Pupitar and Tyranitar have made references to Godzilla. Tyranitar is a very powerful and in the movies/show it can be seen as an unstoppable force. Its appearance and depictions are similar to Godzilla.
 * The Pokémon Kingdra's japanese name is Kingudora (キングドラ), very similar to King Ghidorah's japanese name, Kingu Gidora (キングギドラ).

Generation III References
The third generation of Pokémon were abundant of Godzilla references.

In the Show

 * In an episode featuring Pokémon "Claydol", there was a giant Claydol and it was awakened if the giant rock Pokéball was opened. The main characters opened the Pokéball and the Claydol escaped and wreaked havoc. The group had to encase it in the rock Pokéball in order to stop it. This seems loosely based on King Caesar.
 * In a couple episodes, the Pokémon "Kyogre" and "Groudon" are awakened and they begin to battle. Throughout the entire episodes they begin to fight non-stop and are unstoppable forces. This is very much like the Kaiju fighting in the movies.

The Pokémon

 * Pokémon mascots for Generation III (Groudon, Kyogre and Rayquaza) all are destined to duel if encountered. In the game, it states that Groudon and Kyogre had a battle and the Pokémon Rayquaza was forced to awaken from slumber and stop the two from fighting. This is reminiscent of Kaiju movie plots.

Generation IV
Generation IV seems to be fueled with references to Godzilla.

In the Movies

 * The movie series for this generation are all very similar to Godzilla. They revolve around Dialga, Palkia and Giratina fighting. At first, Dialga and Palkia are awakened, forcing Darkrai to stop them. Dialga and Palkia stop fighting but Giratina got angered and threatens Dialga. Giratina and Dialga fight for a while but they begin to subside. However Arceus the creator of the 3, is going to return and cause destruction of what it created because a subject named Damos betrayed it. Time and space begins to rip and a girl named Sheena summons Dialga to stop it. However another rift in time and space occurs and out comes Giratina. They start fighting but another rip in time and space occurs and out comes Palkia. The three all begin to fight but then Sheena stops the fight and the 3 Pokemon stop fighting. Arceus returns and decides to destroy life. Dialga sends Ash and his friends back in time to stop the end of the world. Arceus fights Palkia, Giratina and Dialga during the time and Arceus wins. Arceus then changes its mind and it decides to spare this world and everything is fine. This entire sequence is reminiscent of Kaiju movie plots.
 * Pokémon Giratina's roar is actually Mothra's chirps, screeches & cries.
 * Palkia's roar is the Boga's roar mixed with King Ghidorah's roar and Godzilla's roar.

The Pokémon

 * Pokémon Palkia is the controller of Space and it is a Dragon Pokémon. This seems similar to King Ghidorah and it is considered a direct reference to it because its roar features King Ghidorah's roar (the Super Smash Bros. Brawl version had one of Godzilla's 1954 roars).
 * Pokémon Yanmega is a dragonfly that evolves from Yanma by learning AncientPower. The fact it is a dragonfly, has mega in its name and levels up through "AncientPower" suggests it is based upon Megaguirus.
 * Pokémon Giratina is the controller of the reverse world and it looks similar to the monster Destoroyah.
 * In the Eleventh movie, the villains' ship (when using it's beam) has the same sound as Megaguirus.

Generation V
Generation V has some references to Godzilla.

The Pokémon

 * Pokémon evo-family with Deino, Zweilous and Hydreigon are all very similar to Desghidorah and King Ghidorah in appearance. The shiny Hydreigon is also green, which is close to yellow on the color spectrum.
 * The Pokémon evo-family Larvesta and Volcarona are direct references to Mothra. Volcarona is a giant moth that is on fire which is similar to the way Mothra dies most of the time.

The Games

 * MechaTyranitar.jpg Pokémon Black 2 & White 2, there is a feature called the "Pokéstar Studios", in which you can make short movies. It has a giant mechanical Tyranitar that can be used in the movies, that goes by the name of "Mecha Tyranitar". This character is similar to MechaGodzilla 2 and late Heisei Godzilla, because of it's stance and appearance.

The Show

 * In the first episode of the Generation V anime adaption, the Pokémon Zekrom has the same roar as Megaguirus while it has Baragon's GMK roar in the 14th Pokemon movie. The Pokémon Reshiram has Megaguirus' roar mixed with one of Keizer Ghidorah's roars in the movie as well.
 * A giant robot that goes by the name "Mecha Tyranitar" appears in the anime. In the very same episode, a giant Tyranitar is shown swimming across the sea. Ash fires at it, removing some of it's fake skin. The Mecha-Tyranitar then reveals it's true self as a robot. This is a direct reference to Fake Godzilla and the movie Godzilla vs. MechaGodzilla. Mecha Tyranitar has Heisei King Ghidorah's roar and is controlled by aliens. Ash Ketchum is a member of the "Unova Defense Force" and lands on an island where two twins talk about restoring a sleeping titan of legend, a giant Golurk. The aliens capture some Pokémon and the twins plead the giant to wake up, but Mecha Tyranitar destroys the sleeping Golurk. Mecha Tyranitar fires a beam at the twins but Golett sacrafices itself. The twins shed two single tears which revive Golett and make it evolve into a giant Golurk. Golurk and Mecha Tyranitar fight, and Golurk uses Mega Punch to destroy the Mecha and uses Psychic to save the Pokemon. The aliens try to beam MechaGodzilla back into their ship but Golurk blocks the beam and later damages the alien ship, making it explode. Golurk lands in front of the main characters and the twins thank Golurk for saving the Earth and all living on it. Golurk restores the Golurk statue and devolves back into Golett. This entire sequence is a direct spoof of kaiju movies, mainly Godzilla ones.

Generation VI
No references to Godzilla have been made so far.

Trivia

 * Toho makes Pokémon movies, and to 'save' time, they reuse Kaiju roars on the Pokémon.