Big biter killer box tested wiht 12 damege 6 speed red ammo. be sure to stay away so there is no lava splashes, lure it to first turrent preferably head on. and step back. can use poison while you run away... so he dose not regenerate. Usualy wont suffer from any fetality maybi some repair and middle colum. So take with you 300 guns, around 3000 red ammo and constant combinators 4 + if you have mines and poison capsules. big worms need 5 ammo to kill in each turrent. evry turrent has 10.