Deadpool's presence on the NES is currently unconfirmed and may reflect a misconception or a fan-made project rather than an official release. There is no record of an officially licensed or released Deadpool game for the NES platform.  Any claims to the contrary should be viewed with skepticism unless verifiable evidence (such as ROM images, promotional materials, or magazine ads) from reputable sources is provided. The likely 'game' would be fan-made or a ROM hack.

Deadpool

Dead Zone (Japan)