This past week has been huge for Pokemon GO. The release of Pokemon Let’s Go Pikachu and Let’s Go Eevee on the Nintendo Switch has introduced some additional connectivity and purpose for the Pokemon players catch in the mobile game, not to mention Niantic also released the Meltan Special Research quest. If all that weren’t enough, there’s a new legendary raid boss appearing in the game world as well, giving players the chance to better complete their gen 4 Pokedex.

Earlier today, the legendary ghost-type Pokemon Giratina left legendary raid battles, and has been replaced by none other than Cresselia. Known as the lunar Pokemon, Cresselia is a psychic-type that will be featured in legendary raids from now until December 18 at 1:00pm PST, at which point it will presumably be replaced by a different legendary Pokemon.

Pokemon GO fans who live in northern parts of the world may be unwilling to brave the cold weather to take on Cresselia in legendary raid battles. Luckily, the game now gives players more ways than ever to add legendary Pokemon to their collection, so missing out on fighting Cresselia in legendary raids isn’t as big of a deal as it would have been a year ago. Nowadays, players can get Cresselia by trading with other players, or potentially through the Field Research breakthrough system at some point in the future.

It’s also possible Niantic will run a special Cresselia Day like it did for the Gen 1 legendary birds. These special events see the featured Pokemon take over every gym for a three hour window, giving players the opportunity to beat and catch a number of legendary creatures in quick succession.

Meanwhile, some Pokemon GO fans may have gotten lucky and already added Cresselia to their collection when it was introduced to the game earlier today. If so, they’re likely looking forward to the next legendary raid boss, though who that will be remains to be seen.

Pokemon GO is out now for iOS and Android mobile devices.