Merely by logging on between May 9th and 13th, players will receive both a Golden Eggnapper and a Golden Devilsaur Egg as a gift. Beyond that, there’s a themed tavern brawl for those clinging on to spring as long as they can.
“In this egg-citing tavern brawl you’ll gather with other Hearthstone players to celebrate the season by dyeing eggs,” Blizzard explained. “One egg will spawn for you each turn, and you’ll get to use a deck of colorful dyes and special Noblegarden cards (plus 10 random class cards) to decorate it. Each dye applies a different buff, and at the start of your next turn your eggs will hatch into something cute. Or a bunny, if you didn’t use any dye (which is still pretty adorable).”
Source: Hearthstone