Not much is known about the Rhino Pirate Shooter's behavior, as attempting to activate its script in the game via hacking will do nothing. It can be assumed that this enemy would have shot cannonballs at Crash with the cannon strapped to its back.
When In Game
After BetaM Reimported The Enemy Its Only Attacks Is Using A Cutlass/Sword To Hit Crash, Throws An Invisible Cutlass/Sword.
Going on the concept art of the Pirate Shooter in the enemy gallery, he would have had the same appearance as the other Rhino Minions in the game, with the addition of a cannon attached to its back.