The M45 Tactical Shotgun, also known as the Zombie Killer you can't use against Zombies, the 'Shotgun', the Noob Obliteration and rarely the M45 Tactical Defensive Offensive Supportive Uber Awesome No-one Will Read This BOOM HEADSHOT Bang Boom One Hit Wonder Smash You're Dead Shotgun. It appears in Halo Reach as a tool for killing BK's and snobs who bought all the DLC. It is vastly improved in Halo 4 as the M45D, and now can obliterate nearly anything.