Slash Beast ("Slash Beastleo" in Japan) is one of Repliforce, a group labeled as Maverick due to their wanting independence. Slash Beast takes care of the train that supplies goods for Repliforce. The battle can be easy or hard depending on what character is being played. As X, the Ground Hunter is the saving grace. The first hit with the Ground Hunter will knock his claws off and it will trap him in a loop. Zero has his work cut out for him in this, as he'll need to keep moving to avoid the charges, slashes, and (when his health is low enough) avoid getting grabbed and shaken like a ragdoll. Zero can hit him with Raijingeki if there is a clear shot.
Enemies in Slash Beast's stage, the Military Train.
Miniboss: Rail Impaler