The green ones, there the Green Meanies. There quite fun to poke at with a chainsaw, and a shotgun. 9 shells does the trick from a 870 16G. He Usually drops a fair peice of loot, DEPENDING how far you go out. In frame 1 you will get a lead pipe.
Big red dudes,Fat Red Ogres (my term), yea, they blow. They usually break your Flak Jacket , and your back, leaving you at Critical and Broken, and send his buddies to try to get you. I shot around 100 16G shells at him, he died somewhere around that amount. He drops a good peice of loot, ALSO depending on the area. In frame 4 he will drops a hunting knife.