[dotancohen]

I believe that the Japanese had an airplane with that designation once, famous for use in suicide attacks, but I cannot find reference to it. Some other models with Zero in the name I can find, but not the P-0.

[HPsquared]

Apparently the Zero was officially the "Navy Type 0 carrier fighter".

https://en.m.wikipedia.org/wiki/Mitsubishi_A6M_Zero