The fully-evolved Gen III starter doesn't usually show its face in Paldean encounters — though you can grab a Mudkip thanks to the Indigo Disk DLC's Blueberry Academy addition, of course — so this is a good chance to snatch one up.
The event kicked off earlier today (or yesterday, for those in North America) and will run until 2nd June before repeating from 6th-9th June.
The starring Swampert has Poison as its Tera Type and holds the Mightiest Mark. As ever, you will only be able to catch this 'mon once per save file.
If you have already caught this special Swampert and want to keep the good times going, new episodes of Pokémon Horizons are now available to stream on BBC iPlayer.
