Following on from April's sheep specific event, May's Pokemon Go community day will feature the fire starter Charmander as its main focus. On May 19, Trainers will finally be able to evolve into a Charizard thanks to increased spanws for the cutest little flame lizard known to man. Just like with the past events, any Charmeleon's evolved into Charizard during the event will learn a special move for battle.
You'll be able to take to your local parks from 11:00 am - 2:00 pm PST and receive 3x the stardust for catching Pokemon as well as have a chance to buy a special Community Day box from the in-game store. Shiny Pokemon seem to have a higher spawn rate during these events, so you'll also be likely to get a shiny Charizard before the day is done. The benefits aren't as pronounced as they have been for past events, but I'm happy to finally be able to find Charmanders in the wild. CT really sucks for any non-basic critters.
Charmander Community Day #5 Guide: May [Pokemon Go Hub]
via destructoid https://www.destructoid.com/may-s-pokemon-go-community-event-is-a-little-fiery-499228.phtml