Pokémon Go's Celebi is the game's second Mythical Pokémon, and was first made available in a different way to any other creature we've seen so far.
Much like Mew before it, it's now available as part of a Special Research quest, where players must complete a series of objectives as part of a story-based questline.
However, there's another key difference - the quest has debuted first for those attending this year's Go Fest in Chicago.
How Celebi event 'A Ripple in Time' works in Pokémon Go
Catching Celebi works much like Mew did back in the first half of 2018, becoming available as part of a Special Research quest line named 'A Ripple in Time'.
Where standard Field Research offers objectives that can be collected by players at any time, Special Research is a story-driven questline with specific steps.
The quest is broken down into eight stages, with multiple challenges to complete per stage. By completing every step of the Special Research quest, the Mythical creature will be given to players as a reward.
Though these are similar to Field Research quests, the specific steps are fixed for every player - so if you don't mind spoilers, you can plan ahead and learn what you need to do to complete them all catch Celebi - which is useful as you'll need to undertake Raid and Gym battles along the way.
To get started, you need to have completed the third group of tasks for Mew's'A Mythical Discovery'. Like Mew, there is no time limit to completing the quest line - so take your time!
What else do we know? There is a focus on Gen 2 Johto Pokémon (in the same way Mew was focused on Gen 1), with the event launching with increased Johto spawns to help complete the quests, as well as the release of Field Research relating to that generation.
If you already caught Celebi by taking part in Chicago's Go Fest, then completing the many tasks will earn you Candy to help power Celebi up.
Additionally, what makes this interesting is Celebi is not the mysterious 'Ultra Bonus Unlock' that is rewarded if player successfully complete challenges across all three Summer Tour 2018 events. So what else could it be?
How to complete Celebi's 'A Ripple in Time' event steps
Here are Celebi's quest steps and their rewards in A Ripple in Time. Be wary of spoilers before continuing, if you are worried about learning what each objective entails before unlocking them.
'A Ripple in Time' Step 1 of 8
'A Ripple in Time' Step 2 of 8
'A Ripple in Time' Step 3 of 8
'A Ripple in Time' Step 4 of 8
'A Ripple in Time' Step 5 of 8
'A Ripple in Time' Step 6 of 8'
'A Ripple in Time' Step 7 of 8
'A Ripple in Time' Step 8 of 8
How Celebi first debuted in Pokémon Go
Before August, only those attending this year's Pokémon Go Fest in Chicago were available to catch Celebi.
Ahead of the July event, datamining (via The Silph Road subreddit) had revealed a Special Research quest for attendees, which confirmed how the following went down:
Once attendees registered for the event (players have to spin a PokéStop and scan a barcade to register their account as attending) they could get started.
Another hint Celebi was going to be at Go Fest is through a sponsored tweet from Mystic7, showing a silhouette of the Pokemon in an event invite.
Celebi stats and what else you need to know about Celebi in Pokémon Go
Celebi is Pokémon Go's second Mythical Pokémon, and the last Pokédex entry in Gen 2. While Legendary Pokémon are powerful beasts that are caught in game through specific steps, Mythical Pokémon can only be added to the game by acquiring it from real-world giveaways, and later in the series, online events.