Green Dragon's Poison Breath ability continues to function until end of turn even if Green Dragon is destroyed or otherwise leaves the battlefield. It takes some time for toxic gas to dissipate.
23-07-2021
wotc
Green Dragon's Poison Breath ability is different than deathtouch. Notably, creatures still need to deal damage to a blocking creature equal to its toughness before dealing damage to another blocking creature or trampling over to a player or planeswalker.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.