Grenade: 0 + explosion
Big John is the second boss of The Facilities. He appears to be a leader of sorts belonging to the military group located in The Facilities, as he bears strong resemblance to the Possessed Soldiers. Unlike other soldiers, he is likely trying to resist the possession as he can be heard exclaiming phrases such as "Kill me!". He is encountered at the end of E2M6: Erebus Reactor, right after the player exits the titular reactor and tries to reach the supernatural elevator to the next level.
Big John is equipped with a high spread assault rifle, which reloads fairly quickly, however, it is relatively short ranged for the arena and the player can often strafe through the shot spread without taking damage. If the player runs back too far he will start firing grenades. These grenades have a special behavior where after a certain number of bounces the grenade shoots straight into the air, resembling a Bouncing Betty in functionality. Big John himself has 5000 hit points, which is 1000 less than Mama, and he can be killed quickly using the Riveter (10 direct hits), or any other higher number weapon.
Big John can easily be avoided due to the large size of his arena; one can lure him out and then run into the elevator he guards. Big John has no move room left or right in his waiting room, so a player can kill him with minimal risk using 25 crossbow shots. There is a full supply of crossbow bolts as a secret on top of one of the reactor pillars.
- Big John's face texture is derived from Dave Oshry's Twitter image. 
- Big John is voiced by New Blood Interactive CEO Dave Oshry. Big John's voice files come from another project which Dave Oshry worked on in 2013, Rise of the Triad.
- Big John has cameos in most New Blood Interactive game released to date. He always is a boss enemy, except for ULTRAKILL, in which he appears as a custom texture for the Cyber Grind mode.
- Big John is a parody of the character Alan Dutch from the classic 1987 movie Predator.
- Big John's boss theme is Murder Machine Inc., shared with Mama from the level before.
- His wide-bore rifle bears a strong resemblance to the BFG 9000 from classic Doom, albeit with a rifle stock.
- "Kill me! Kill me, c'mon!"
- "C'mon, kill me!"
- "Come here, kill me!"
- "Come and kill me!"
- "Yah, girly man, hahaheaugh!"
- "Yahaha, Big John, haha, yeah, that's me."