Niantic has been pumping new life into Pokémon GO over the last few months, and with the upcoming raid event for Kleavor, there's no sign of that stopping. The Axe Pokémon is scheduled to arrive on May 6th during a special Raid Day event to celebrate. While players will certainly be able to catch it after the Event, their best chance is to do it during a brief three-hour window.
https://screenrant.com/pokemon-go-kleavor-raid-event-dates-times-rewards/