Rules: same as the other letter evolutions. If you need help, take a look at this: https://www.motherjones.com/wp-content/uploads/2019/03/blog_zebra_alphabet.jpg?resize=990,577 or the graph in my project
![On Beyond Zebra letter evolution [ Um --> Humpf ]](https://cdn2.scratch.mit.edu/get_image/project/343513934_480x360.png)
