From Bulbapedia, the community-driven Pokémon encyclopedia.
Jumbo cards (Japanese: ジャンボカード Jumbo card), also occasionally referred to as Oversized cards, are a variant of Pokémon card released for the Pokémon Trading Card Game. These cards are strictly promotional and not legal for Organized Tournament play. As the name suggest, Jumbo cards are much larger in size than standard, regular-sized cards, varying from slightly larger than a normal sized card to a height of at least eight inches. In Japan, most Jumbo cards are given out at exclusive events, such as a Pokémon Center grand reopening or JR Train Stamp Rallies. Although this type of release method is possible for the international languages, the more common release method is in merchandise, such as the Garchomp-EX Box or the Dialga Premium Box. Although all produced and distributed by The Pokémon Company International, the international Jumbo cards aren't always consistently the same: some products will switch out their Jumbo cards for others when released in Europe.
As they aren't ever intended for tournament play, Jumbo cards are often given certain characteristics impossible for tournament cards. In English, there are four Jumbo cards printed as lenticular images (_____'s Snivy, _____'s Tepig, _____'s Oshawott, and Zoroark), giving these cards an exclusive 3D appearance. Starting with the XY Series, The Pokémon Company International was no longer able to release figures in their TCG products when distributing them to European audiences. Thus, while North American audiences receive products with figures, such as the Mega Charizard Collection, Europe instead receives products with the figures replaced with Jumbo cards, i.e. the Mega Charizard Box.
List of Jumbo cards
X & Y Era
Sun & Moon Era
Sword & Shield Era
Starting with the Sword & Shield era, jumbo cards were released in a slightly smaller size than previous eras' jumbo cards. With this change in size, The Pokemon Company released the first ever official oversized card binder for these smaller oversized cards.