The official Pokémon has announced that they will be distributing 4 Promo Card at Pokémon TCG: Sword & Shield Prerelease tournaments which will be held from January 25th, 2020 until February 3rd, 2020. Participants in the tournament will be able to get 1 of 4 cool promo cards:
Rillaboom (SWSH006),
Frosmoth (SWSH007),
Galarian Perrserker (SWSH008), or
Cinccino (SWSH009).
Pokémon TCG: Sword & Shield Prerelease Promo Cards Feature Galar Pokémon
Pokémon TCG Prerelease tournaments let players be the first to get their hands on the newest expansion and try out the latest cards in action. With the launch of the new Sword & Shield Series, Prerelease tournaments will be your first chance to play with Pokémon from the Galar region. Pokémon TCG: Sword & Shield Prerelease tournaments will be held January 25 – February 3, 2020, shortly before the expansion launches on February 7. In addition to getting cards early, you'll be able to pick up 1 of 4 cool promo cards: Rillaboom, Frosmoth, Galarian Perrserker, or Cinccino! Check with your local game store to see when they're hosting one of these events.
When you sit down to play at a Prerelease tournament, you'll receive a Build & Battle Box containing a 23-card Evolution pack, which includes an exclusive foil promo card and is designed to give you a strong foundation for building a new deck. Each box also includes four 10-card booster packs from Sword & Shield. You'll use these cards, plus basic Energy provided by the Tournament Organizer, to construct your own 40-card deck. You'll get to keep all the cards from your Build & Battle Box, whether you use them in your deck or not. If you're lucky, you might even open one of the new out-of-this-world Pokémon V or Pokémon VMAX.
The promo card you'll receive is a cool collector's item, with a shiny foil stamp marking it as a Prerelease promo. It can also be used in your deck, and you're likely to wind up with plenty of cards that match its type. Take a look at the four promo cards available at Sword & Shield Prerelease tournaments, and get some tips to make the most of the one you receive.
Rillaboom (SWSH006)
Sound off with the Grass-type Rillaboom, the final Evolution of Grookey. Its Voltage Beat Ability is super useful no matter the tournament format, allowing you to quickly get lots of Energy onto your Pokémon by grabbing 2 Grass Energy cards from your deck and attaching them to 1 of your Pokémon. Rillaboom will happily take that Energy for itself so it can power up its hard-hitting Hammer In attack. You're less likely to come across super-powerful Pokémon V in Prerelease tournaments, so 140 damage is likely to be enough to Knock Out a lot of foes in one hit.
Frosmoth (SWSH007)
Like Rillaboom, the chilly Frosmoth helps keep your Pokémon full of Energy with its Ice Dance Ability. It lets you attach a Water Energy card from your hand to your Benched Pokémon—and keep doing that as often as you like during your turn, powering them up quickly so they're ready to attack. Frosmoth is a Stage 1 Pokémon, meaning it's even easier for it to show off its moves. And remember, it doesn't have to be Active to use this Ability; Frosmoth can make an impact even when it's out of the spotlight.
Galarian Perrserker (SWSH008)
The Meowth of the Galar region take on a hairy new look and evolve in a new direction—Galarian Perrserker! This Pokémon sharpens the attacks of any of your Metal-type Pokémon (including itself) by making their attacks do 20 more damage. In a Prerelease tournament, every little bit helps, and a couple of these Pokémon on your Bench can make a massive difference in battle. At 120 HP, Galarian Perrserker is rather durable, too, making it potentially effective in the Active Spot and attacking with Metal Claw for a boosted 90 damage.
Cinccino (SWSH009)
The only Pokémon from this lineup who wasn't discovered in the Galar region, Cinccino has some useful skills to contribute to your Prerelease deck. Its Make Do Ability lets you turn over your hand by discarding a card to draw two more. Remember that you have only 40 cards in a Prerelease deck, so make sure you don't draw yourself out of cards. Speed up your Energy attachment by discarding an Energy with the Ability, then getting it onto a Benched Pokémon with Cinccino's Energy Assist attack—which also does 40 damage.
Source:
https://www.pokemon.com/us/strategy/pokemon-tcg-sword-shield-prerelease-promo-cards-feature-galar-pokemon/