Regigigas is a very large Pokémon that bears a similar resemblance to the other three Regi Pokémon. Primarily white, Regigigas have a few black stripes located on their body and yellow plates surrounding their wrists, shoulders, and another in their upper region. Around its feet and its back, Regigigas have some kind of plant or moss growing on it. It has a very large physique with long arms, short legs and no visible neck or head. Unlike the other Regi Pokémon, Regigigas have no specific element that they relate to. Instead, they have two sets of three gemstones, with a set representing Regice, Registeel, Regirock and Dark Regigigas.
This creature is also the master of Hoenn's Legendary Regis. It remains dormant in Snowpoint Temple until the player arrives with Regirock, Regice, and Registeel in their party.
There is only one that can be found in the Generation IV games. It can only be awakened and caught in the basement of the Snowpoint Temple when the player has the other members of the Regi family in their party. (The only way to acquire the other three Regis in Generation IV is to beat the Elite Four, and migrate them into Pal Park.) There was also a Pokémon Diamond and Pearl event in which you could obtain Regigigas. In the Platinum version, there is a special event where you can find the other three Regis using the event Regigigas only. Regice is located in Mt. Coronet (near Route 216), Registeel on the B3F of Iron Island and Regirock is located on Route 228. When you caught all three, go back to Snowpoint Temple and battle it (It is encountered at Lv. 1). This is the best way to get it in Platinum.
Regigigas made an appearance in the 11th Pokémon Movie, Giratina and the Sky Warrior. It awoke from its temple and, along with a herd of Mamoswine, it helped hold back a glacier Zero had broken to destroy the Gracidea Garden. After the glacier's foundation in the Reverse World was restored, Regigigas went back to its temple.
Just as Diamond is about to jump to the hole to the other universe, Regigigas came out and stopped him. In Pokémon Diamond and Pearl Adventure!, Hareta catches a Regigigas in the 4th Book to battle Team Galactic.
Regigigas is the only member of the Regi family not to have its type included in its name.
Regigigas is one of the most powerful legendary Pokémon in the games and the movies, though its ability, Slow Start, prevents it from accessing its true power for 5 turns, in which case its power is halved, as shown in Giratina and the Sky Warrior, where it couldn't push back the iceberg even though it said that it towed the continents into place.
In addition, Trick Room can also make Regigigas the fastest one on the field for about the same amount of turns as Slow Start stays in effect.
There is a misconception involving Regigigas' eyes. While many think that it's eyes are the six colorful spots on its body, it's eyes are actually the black dots on its gold crest. The six spots serve no purpose other than hinting at Regigigas' control over the other Regis.
Like the other Regis, Regigigas is weak to a Fighting-type.
Regigigas is based on the "Regis" or "Golems" described in Hebrew legend. These legends depict them as servants of higher powers, and are also said to have writing on their heads. When this writing is removed, the beast would be weakened.
Regigigas's is a combination of the words "Regi", the Esperanto word to rule, to reign, to govern, to control, combined with the word, "gigas", meaning giant. Therefore, a rough translation could mean "King of the Giants",as it needs to get the three other "Regis" to awaken this.