That's air dry clay, also called super light clay or foam clay. The kind that comes in sealed pouches like these.
*What makes it popular:* - *Feels soft*: It's squishy and lightweight, almost like marshmallow foam - *No baking*: Hardens by itself in 24-48 hours just left out in the air - *Bright colors*: You can mix the colors together to make new shades
*What people make with it:* People use it for slime mix-ins, mini charms, fridge magnets, and simple figures. Because it's so light, it works great for things like cake toppers or keychains that won't weigh much.
