The Pokemón Company put out a press release and video today detailing the new Gigantamax mechanic in Pokemón: Sword and Pokemón: Shield as well as four new Pokemón coming to those games. Essentially, Gigantamax is a thing that some specific Pokemón where they temporarily grow and grow until their Kaiju size.
These are the latest Pokemón in the Pokedex:
Alcremie, a Fairy-type that looks like a dollop of whipped cream with a face. Alcremie can produce whipped cream which it uses to distract and temporarily blind opponents and has a Gigantamax version that can heal its teammates.
Yamper is an Electric-type puppy Pokemón. They can fetch the first failed Pokeball thrown at another Pokemón and generate electricity by running. Yamper does not have a Gigantamax version, at least one was not revealed at this time.
Rolycoly: the latest Rock-type coal Pokemón, who gets a speed boost when hit with fire attacks and has a light producing eye. No news on weather Rolycoly can Gigantamax.
Duraludon the new Steel/Dragon-type on the block who lives in the mountains and has been known to battle with Tyranitars. Duraludon has not been reported to have a Gigantamax version.
Gigantamax, not to be confused with the already announced Dynamax, is a new mechanic for the coming Pokemón: Sword and Pokemón: Shield games where some Pokemón can grow to enormous size and change the way they battle. Gigantamax is different from Dynamax, a mechanic that also lets Pokemón get big, in that all Pokemón can Dynamax but only a few can Giganamax. Dynamaxing can also only happen in specific spots on the map while Gigantamax Pokemón can get big wherever they want. And finally, Dynamaxed pokemon are simply bigger, stronger versions of their normal size selves while Gigantamaxed Pokemón change appearance and get new special moves.
You can catch these new Pokemón in Pokemón: Sword and Pokemón: Shield exclusively on Nintendo Switch starting November 15, 2019