Sure, here's an example of a Flappy Bird game with a Five Nights at Freddy's theme implemented as a single HTML file:
To use this code, save it as a `.html` file and place corresponding images (`emozi_all/chicken.png`, `emozi_all/bird.png`, `emozi_rabbit.png`) in the same directory as the HTML file.
Please note that this implementation is a basic demonstration and may require enhancements to match the full gameplay experience of Five Nights at Freddy's or Flappy Bird.