Groudon did not originate from fanon, and the information on this page may not be entirely accurate to their canon. You may read more about this subject in the context of their canon on the following wiki(s):
Groudon, known in Japan as グラードン (Groudon), is a Legendary Ground-typePokémon. Groudon is known for its ability to expand the land, and has feuded against Kyogre in ancient times. Together with Kyogre and Rayquaza, it forms a trio of super-ancient Pokémon, each hailing and guarding one respective type of elemental sphere (Groudon's being the lithosphere).
Groudon can undergo through Primal Reversion, to become the Ground/Fire-typePrimal Groudon using the Red Orb, which is said to be its original form.
Groudon is an enormous, dinosaurian, bipedal Pokémon, covered in red segmented plating, which is so thick, it's used as an armor. It has a gray underside and large white spikes that rims on the sides of its body. It has four claws on its hands and three claws on its feet. Its broad tail ends with four flat, pointed blades which collectively resemble the blade of a bulldozer. On its forehead are four blades, which merge together at the tip of its nose. Its eyes are inside the seams of its head's armor, having yellow sclera and black, round pupils. Inside the seams of its plated armor are black stripes, which glow blue when Groudon is bursting with power.
Groudon apparently created the land of the Pokémon world, and is known for expanding continents. It has the ability to let the sun break through the stormiest of clouds, and make the sun shine so harsh that bodies of water evaporate extraordinarily fast. Because of this, Groudon is seen as a savior by the people that suffered from monstrous rain floods, but can also be seen as a pest by the people suffering from overly long drought. It is the opposite of Kyogre, who it feuded against long ago. After this everlasting fight, Groudon went asleep for ages in underground magma. It is said that it makes volcanoes erupt when it awakens after this deep slumber.
When Primal Reversed, Groudon becomes much larger (and heavier) than before. The black stripes, as well as its pupils, now glow yellow like lava, and its sclera have become fire red. The lava-like glow reappears in its mouth, and stripes with the same glow have appeared on the gray underside. Its plated body has turned more crimson, and its underside, teeth and spikes all turned dark gray. The spikes and blades on its tail have been skewed upwards and sideways, making its tail almost spoon-like. The patterns on its forearms now resemble an uppercase Omega.
This appears to be Groudon's original form when it battled against Kyogre centuries ago. The glow of its stripes appear to be Groudon's energy, which streams through its body like molten magma. These stripes burn with such amazingly high temperature, that its body always emits a strong heat. Its Ability also gains an amazing boost in power. It can attack its opponents by raising enormous rock spears out of molten magma.
In this form, Groudon battled Kyogre for ages and ages, as both of them wanted more and more energy for itself. As they already have strong natural energy in possession, each of their duels brought the inhabitants of Hoenn in danger every time, and the people of their time called Primal Groudon and its rival tormentors.
Minimum stats are calculated with 0 EVs, IVs of 0, and a hindering nature, if applicable.
Maximum stats are calculated with 252 EVs, IVs of 31, and a helpful nature, if applicable.
By level up
Lowers the target's Speed stat one stage.
High critical hit ratio.
Lowers the target's Speed stat two stages.
Summons sunny weather for 5 turns.
Raises the user's Attack and Defense stats one stage.
No added effect.
Sleeps for 2 turns, restoring HP and status problems.
30% chance of burning the target.
Prepares the first turn and strikes the next turn.
10% chance of raising all of the user's stats one stage.
No added effect.
10% chance of burning the target.
10% chance of lowering the target's Special Defense stat one stage.
Lowers the user's Speed stat one stage.
Causes a one-hit KO.
Causes less damage the lower the user's HP is.
Primal Groudon is the heaviest Pokémon.
Groudon shares its species name with Torterra. They are both known as the Continent Pokémon.
In Pokémon XD: Gale of Darkness, the character Chobin operates a Robo Groudon after the player defeats him for the third time.
Groudon is the only Generation III Legendary Pokémon to have never appeared in any movie (only in introductions, though a fake one appears in the Jirachi: Wish Maker).
This "Groudon" is much taller than its game height of 11' 06", being as tall as the mountainous structures in Forina. When an actual Groudon later appeared in the anime series, it is much closer to its correct size.
On the DVD cover of Jirachi: Wish Maker, a normal Groudon is depicted, despite the Groudon in the film not being an actual Groudon.
Although Groudon is genderless in the core series games, it is referred to as a male in Pokémon Mystery Dungeon: Explorers of Time and Explorers of Darkness.
A Groudon costume is worn by Terrell in Pokémon Battle Revolution.
Primal Groudon has the highest base Attack and Special Attack of any Ground-type.
Groudon is most likely based on the land master Behemoth, of Hebrew legends, which counterparts, Leviathan and Ziz, mirror Groudon's counterparts of Kyogre and Rayquaza. Despite this, Groudon doesn't resemble the traditional depiction of Behemoth, who seems to be a cross between a hippopotamus and a warthog.