April Fool's might be a time-honoured tradition, but it's also generally a bit of a risky area for brands - only a carefully planned joke can avoid any ill-will if it's aimed wrong. Pokémon Go has taken a different route in recent times, eschewing jokes entirely.

Instead, it has an annual April Fool's event that comes around for a day each year, and it's back for 2021. It runs all day on your local time, and means that your routine might be a little different to normal. 

Throughout the day you'll see more Pokémon known for their mischevious natures in the wild, meaning creatures like Aipom, Croagunk, and Purrloin among others. Plus, you'll also run across Ditto far more frequently during the event, and it'll be able to disguise itself as Pokémon that it hasn't so far masqueraded as on Pokémon Go. 

You'll also see a lot more of Team Go Rocket and its grunts for the day's duration, and their teams will all feature Shadow Aipom. In terms of goals, there's a new Team Go Rocket Timed Research to complete - if you manage to do so, you'll earn a Super Rocket Radar and some other rewards to boot. 

The full blog post from Niantic has some more hints about what you can do to make the most of the event, including the tidbit that you should try taking some screenshots while you play to see what happens.