The Galarian starters’ final stages are about to get their Gigantamax forms in Pokemon Go, beginning with the Grass-type Rillaboom. Here are all the details you need to know to add it to your Pokedex.
Since the Max Out Season introduced Dynamax and Gigantamax Pokemon to Niantic’s game, these enormous creatures have continued to debut once every other month.
However, to give worldwide players a treat as the Go Fest 2025 in-person events unfold, the Galarian starters – Rillaboom, Cinderace, and Inteleon – will get their Gigantamax forms with special global free-to-play events.
Gigantamax Rillaboom will be the first, as it will appear in the Serene Retreat, so check how to take it down, to then attempt a catch!
Gigantamax Rillaboom weaknesses in Pokemon Go
As a pure Grass-type Pokemon, Gigantamax Rillaboom is weak against Bug, Fire, Flying, Ice, and Poison-type moves. Luckily, there are plenty of D-Max and G-Max creatures in the game who boast those types, so players will have an easy time building their ideal team.
Nonetheless, it’s worth noting that they should avoid using any Pokemon with Electric, Grass, Ground, or Water-type attacks, as they won’t be able to deal significant damage.
Remember that only fellow Gigantamax or Dynamax Pokemon are eligible in Max Battles.
Gigantamax Rillaboom best counters
Even though Dynamax and Gigantamax Pokemon are still very new to the game, there are plenty of good choices available to take G-Max Rillaboom down.
The absolute best choices are Gigantamax Charizard and Dynamax Moltres, as they will be able to target Gigantamax Rillaboom’s Fire and Flying weaknesses.
If you are missing any of those, you can go for their alternate forms (in G-Max Charizard’s case) or switch to another Pokemon form the list. Remember that overall, Gigantamax forms are superior, as they deal way more damage than their Dynamax counterparts.
How to get Gigantamax Rillaboom in Pokemon Go
Gigantamax Rillaboom will debut during the Serene Retreat event, which will run from Friday, May 30, 2025, at 10:00 AM until Tuesday, June 3, 2025, at 8:00 PM local time. This is a global free-to-play event that will be celebrated in parallel with the Go Fest 2025 Osaka in-person event.
During that time, G-Max Rillaboom will appear as a 6-Star Max Battle boss, and players can challenge it as many times as they want.
Keep in mind, though, that as of May 13, players can join Max Battles remotely. This means they can use Remote Raid Passes to jump into Power Spots from wherever they are.
To join a Gigantamax battle, players must pay 800 Max Particles, which can be collected from visiting such Power Spots daily. If you fail to defeat the Max Battle boss, the MPs will be returned so you can try again.
It’s worth noting that these special creatures cannot be caught in their gigantic forms, so after defeating Gigantamax Rillaboom, trainers will have the chance to try and catch a regular Rillaboom with the Gigantamax ability.
How to evolve Rillaboom into Gigantamax Rillaboom
While Gigantamax Pokemon are stronger forms of a particular creature, they are not considered evolutions, as they are temporary forms that are limited to battles.
This means players cannot evolve Rillaboom into Gigantamax Rillaboom. Instead, they can defeat and catch a regular Rillaboom with the Gigantamax ability. That way, when they use it in a Max Battle, it will turn into its enormous form for as long as the encounter lasts.
DEXERTOGigantamax Rillaboom CP in Pokemon Go
As with every Raid Boss in the game, the CP Gigantamax Rillaboom has during a Max battle won’t be the same once you manage to catch it after defeating it. Plus, certain types of weather can increase such CP.
| Max Battle Raid boss CP | TBD |
| CP range once captured | 1817 – 1899 |
| Gigantamax Rillaboom max CP (Level 50) | 3758 |
Gigantamax Rillaboom stats & moves
As a pure Grass-type Pokemon, Gigantamax Rillaboom has the following stats:
| ATTACK | DEFENSE | STAMINA | CP |
|---|---|---|---|
| 239 | 168 | 225 | 3758 |
Fast Moves
- Razor Leaf (Grass/STAB)
- Scratch (Normal)
Charged Moves
- Grass Knot (Grass/STAB)
- Energy Ball (Grass/STAB)
- Earth Power (Ground)
- G-Max Drum Solo (Grass/STAB)
Can Gigantamax Rillaboom be Shiny?
No, Gigantamax Rillaboom cannot be Shiny in Pokemon Go, as of yet.
Typically, Shinies debut a year after their regular versions, and since Grookey (Rillaboom’s base stage) was introduced in September 2024, players will likely have to wait until 2025’s second half to see if its Shiny version is unlocked.
DEXERTOOnce it does, Shiny Rillaboom and subsequently Shiny Gigantamax Rillaboom will be relatively easy to spot as their deep green grassy details change to lime green.
Anyhow, remember that the odds of coming across a Shiny Pokemon are very low, and there’s no special method to secure an encounter.
That’s all there is to know about Gigantamax Rillaboom in Pokemon Go. For more on the game, check out our guides to stay updated with the Spotlight Hour schedule and event calendar, as well as the upcoming Community Day.
