First of all you need to obtain the following weapons and items:

Required:

- Cowhead. This is absolutely the most important weapon you need, because it's super effective. Here some place where you can find it:

Hospital;



BullFish Interactive;










Vince's House;



Dog Pound.










- WMD. The best rocket luncher in the game, it's indispensable in the boss battle. You can find it only in two place:

Military Base;
Towards the end you will find this big hangar, in one of the first "room" (see image) you will find a box with inside of it the WMD.







The WMD in the box.









During the Apocalypse (after the Military Base level).
At the start of the level (when the red taliban is on the roof), kill all and on the left wall you will find a SledgeHammer;








Use it to break the Chinese Restaurant doors (see image);









Go through the room and reach the stairs "Employees Only", then go up;









On the last table there will be the MWD.









- Pistol. You need this just for destroy Gary's Coleman heads, but you can also use a Machine Gun.


Optional:

- CatNip: It's not absolutely necessary, but it's very usefull and make everything a lot easier. You can find a lot of it in the Hospital:



- KrotchyNades. You just don't need this, it's something like "the last resource", when you have no Cowhead and WMD ammo left and the boss still alive. You can find them in Vince's House:

Find the start of the wire and follow it;









At the end you will find the KrotchyNades, a SiC Body Armor and two health pipes.








Note: the KrotchyNades are the best grenades but they also have the biggest range of explosion, pay attention when you throw one of them or you can be killed by the explosion.

"I am Mike J, Kosher Mad Cow Zombie, God of Hellfire! All bow down, and worship my asscock!"

There we go, now you have everything you need for the final battle... Are you ready?
Let's do this! When the battle begin the first thing you need to do is to destroy the Gary's Coleman heads, because the Boss is invulnerable until this stupid heads still flying around him.
When the heads are destroyed you can start the Cowhead-WMD combo, you will need to go in this order:

1) USE THE CATNIP! I alredy say that, but it make everything a lot easier, you better use it;

2) Start throw the Cowhead. The max number of ammo is four, so be carefull when you throw it, because you will not have a second chance. I suggest to throw two of them on his body and two of them near the foot, it will be very effective;

3) FINISH HIM! After you throw the Cowheads you will immediately see that the HP will start to drop drastically and now it's time for use the WMD. Start shoot him repeatedly, until he finally die (you waybe can ask me: why I need to use this rocket launcher and not just a simple RPG? Well, this special weapon is able to infect the target when get hit, this mean the victim still get damage and this make it a very efficient weapon).


And there you go, you beat Mike J...
When you know how to do that, isn't really hard, right?