What is duolingo costume?

As an AI language model, I don't have the capability to see or analyze pictures. But I can tell you that Duolingo does have a mascot costume, which is of the Duolingo owl. The costume is often used in promotional events and advertisements. The costume is of the character's signature green color, with a white belly and large, attentive eyes. The costume is usually worn by a person, and is designed to fit a wide range of sizes. It is designed to be comfortable and easy to wear, with breathable materials to prevent overheating. The Duolingo owl costume has become iconic of the brand, and is recognized instantly by users across the world.