Ex-Packers QB Seneca Wallace -- Check Out My Japanese Penis ... Cookie!

Seneca Wallace went to Japan ... and all he got was this weird black penis cookie.

The former Green Bay Packers QB -- along with other NFL stars -- went to Asia recently to visit U.S. troops stationed abroad. But when the guys stopped in the Land of the Rising Sun, they stumbled upon an interesting cultural artifact ... baby penis cookie (chocolate flavored).

We ran the cookie box by our in-house Japanese expert (Yori our camera guy) ... who tells us the Japanese word at the top of the packaging translates loosely to "weiner."

Seneca tells TMZ Sports he wasn't offended by the black penis cookie ... partially because "there was a vanilla flavor with a white baby on the cover."

Japanese desserts -- extremely weird ... but not overly racist!