Actor Aidan Gallagher recently promoted the launch of The Umbrella Academy with an Instagram video in which he explains the premise of the new Netflix series while eating a peanut butter sandwich stuffed with Dandies vegan marshmallows. “The world is ending. I’ve seen it,” Gallagher said after describing the series, which is centered around a family of superhero misfits. “There is no hope for any of us because you know what? My family is a mess,” Gallagher said before taking a bite of the vegan sandwich. The 15-year-old actor frequently urges his one million Instagram followers to consider going vegan, sharing motivating posts about climate change and pollution. At age 14, Gallagher was named the youngest UN Goodwill Ambassador for his efforts to educate his peers about the devastating environmental impact of animal agriculture. “I found out that the animal agriculture business has a huge impact on our climate, so by cutting down on your meat and dairy consumption, you can have a huge impact and help the environment,” Gallagher told Fortune. “One hamburger uses a ton of energy as well as a lot of water to create, so by eliminating that from your diet you’re affecting a lot of change.” The actor transitioned to veganism after his family adopted Meatless Mondays, which evolved into a vegan challenge—a lifestyle change that Gallagher decided to adhere to permanently.