One my client from Australia runs a children school and in this task asked me to create a complete English alphabet (both small and capital letters), so that he could use it everywhere in educational process. The only wish he had is that alphabet should be unique and suitable for kids.
Among the other versions (there were three different alphabets created), I've made this one - some letters look like fish, some contain fish, some are adjusted with fish pattern.
All the letters look in the same concept, the pattern is recognisable, and there are so much details in the letters, that makes the alphabet even more valuable to kids - one can observe each letter for a long time.
Surely, the alphabet cannot be used as a font in daily life (without colours and internal pattern it loses most of its charm), but in educational purposes for small children it is more than suitable.