I quickly pull out a molotov and chuck it at it, along with rolling a pipe bomb off to the side to distract the normal zombies so they'll at least slow it down a little. I start to climb, quickly, before the tank can get the chance to throw a chunk of rock at me, like he seems to love to do. I watch him start smacking zombies to the side. Good. It did slow him down some. I continue climbing, trying to reach the top as fast as possible.