cosplayer, Asriel Dreemurr costume, furry, goat-like features, horns, long ears, green and yellow eyes, heart locket, striped shirt, fluffy tail, standing pose, playful expression, fantasy setting, colorful flowers, grassy field, magical atmosphere, soft lighting, full body shot, dynamic angle, vibrant textures, detailed fur, high-resolution, afternoon sun, clear sky, immersive environment, Undertale theme, child-like innocence, action pose, holding a toy knife, determination.