After encountering the Legendary bird trio at Dyna Tree Hill, Galarian Articuno will start roaming the Crown Tundra. You’ll know it’s nearby when you hear its cry as you enter or re-enter the tundra (typically via flying taxi). The louder the cry, the nearer it is to you.
Articuno’s location can vary, but we recommend sticking to one place. Keep using the flying taxi to fly to the same place, until Articuno spawns right near you. We had the most success flying to the Watt Trader by the entrance of Snowslide Slope. Once Articuno spawns, you need to follow it until it stops, since it’s airborne and you’re not.
If it spawns near the Snowslide Slope entrance, you need to chase it towards the side branch, through the tall grass, just before the slope to the Tunnel to the Top. You actually don’t need to physically follow it, because it takes a pre-determined path, so you can head to the destination to wait for it.
Once Articuno reaches its destination, it will create three images of itself. Two are fake and one is real. The real one will spread its wings briefly and utter a cry, then all three Articuno images will spin rapidly. After a while, the Articuno will slow down and you can bump into the Articuno that you think is the real one.
After making your choice, the Articuno images will disappear. If you picked the correct one, Articuno will reappear and hover in the air for a moment while making a cry. Then it’ll vanish again, before suddenly attacking. Choose wrong (or take too long) and the true Articuno will fly away and you’ll need to repeat the process.
If you have good eyes, you could try to follow the real Articuno. Otherwise, you’ve got a one in three chance of being right. Which isn’t bad, considering. Or if you’re feeling crafty, you can save your game before Articuno creates its illusions. Then reload your save file if you chose the wrong one.
Articuno’s Galarian form has swapped from Ice-type to Psychic-type. It’s weak to Electric, Ice, Rock, Dark and Ghost. Move-wise, it can use Freezing Glare, a new Psychic-type move that can cause Freeze, Hurricane, Psycho Cut and Psycho Shift. Its Competitive Ability boosts its Sp. Atk if its stats are lowered.
It’s still early stages, but Galarian Articuno seems like a marked improvement over the original. Psychic-types are generally great and it being Psychic/Flying gives it a huge advantage against scary Fighting-types. It has a solid stat spread, with excellent Sp. Attack, and a useful Ability to scare opponents who rely on lowering stats.
Anyway, we’re here to catch this thing, right? In terms of defense, Dark-types are great, to shrug off Freezing Glare and Psycho Cut. The latter runs off Articuno’s weaker Attack stat, but if it criticals, it can hurt. You should be wary of Hurricane, but it has low accuracy unless you’re in a raining zone.
Steel-types are another great pick, as they resist all of Articuno’s moves. Although you’ll want to pick one with high Sp. Defense. If you’re struggling to think of something, Registeel from the Regi quest makes for a great wall. You also won’t have to worry much about fainting Articuno, since the Regi has low Attack.
By this stage, you ought to be pretty familiar with catching Legendary Pokémon (unless you skipped straight to this quest). Our routine was inflict paralysis with Nuzzle, then gradually weaken it down with weak moves. Use False Swipe if possible, to get it down to 1 HP. Then, if you haven’t already, switch to your Dark or Steel-type to absorb Articuno’s moves.
Watch out that Articuno can use Psycho Shift to transfer its paralysis to your Pokémon. There are two ways to handle this. One, you could keep an Electric-type in front (since they’re immune). A high level Morpeko (eg. from Challenge Beach or Ballimere Lake) could be useful, since it’s Electric and Dark. Two, let your Pokemon be paralysed and inflict paralysis again; Psycho Shift won’t work if you’re already paralysed.