The latest episode of the Pokemon anime has confirmed that Meowth from Team Rocket has a Gigantamax form.
Pokemon Sword & Shield introduced Dynamax and Gigantamax forms for Pokemon. The Dynamax power-up turns a Pokemon into a giant, which drastically increases their stats and alters their moves. There are certain Pokemon with special Gigantamax forms, which alters their appearance and gives them access to incredibly powerful G-Max moves. Meowth was one of the first Gigantamax Pokemon revealed in Pokemon Sword & Shield.
The Pokemon anime has revealed that Ash's Pikachu has a Gigantamax form, and another long-running member of the cast also has that power. The current story arc of the Pokemon anime is based on Sword & Shield, with Ash and Goh traveling to the Galar region. A preview clip of the recent Pokemon episode on the Pikachu Master YouTube showed Meowth turning into its Gigantamax form, and we now know why it happened.
In episode 44 of the Pokemon Journeys series of the anime, Chairman Rose causes the Darkest Day event to happen in the Galar region. This causes Pokemon around the region to start Dynamaxing against their will. Meowth is affected by the event, causing him to Gigantamax for the first time and go berserk. He spends the rest of the episode pursuing Jessie, James, and Wobbuffet.
One of the easiest ways to earn money in Pokemon Sword & Shield is with a Gigantamax Meowth using G-Max Gold Rush during the post-game battles. Team Rocket won't be able to benefit from this tactic, as it was established that Meowth can't learn Pay Day, due to his ability to speak. It's been speculated that Team Rocket's Meowth can Gigantamax ever since the form was revealed for the first time, and it's nice that the theory was confirmed, even though it likely won't be a major plot point. The only question now is whether he will face off against Pikachu's Gigantamax form, in the Godzilla-style battle that has been promised since the early days of the anime.