Ninjas prayer.

http://en.wikipedia.org/wiki/Ninja

A simple (yet very massive obstacle) is in your way Jonathan. It's language. If the collective class of ninjas had a shared litany of prayers or a single shared prayer and if it was in fact documented (as opposed) to some kind of oral history tradition (passed on verbally only from generation to generation), it's still going to be in Japanese.

You probably going to have to hit some serious high academic level history books to get a translation of the prayer or (most likely) prayers if they did in fact were an institutional practice before each battle.

Try using spirituality, battle, and Japanese history in your library catalog search. Best bet is to circumnavigate the library's catalogue system and ask the reference librarian. And by library, a small town library or collective library group might not have what you're looking for. Does your town library have an interlibrary program with any college or university libraries nearby? That ultimately is your best bet.

Then again, you still might face the problem of running into the possibility that any English translations still haven't been published yet. So then get cracking on learning to read Japanese.

dunno about a prayer, but they have a song...

http://www.youtube.com/watch?v=CETZmfTw-j0&feature=related

Ninja cows...

http://news.yahoo.com/blogs/sideshow/ninja-cow-beguiles-nebraska-town-162519267.html

I have not been too the library in a long time. Nor have i read a book in a while.
I will try with the local library , but i don't expect much of it.
I don't see translation as that big of a problem.
Since there are many translators on the internet.
As long as i can read it and know it's meaning then i am happy .