<p>Zen Headbutt can replace Aerial Ace.</p>

<p>The same concept as the one before, however this is more physically oriented. Thunderpunch gives you the ability to take on Gyarados will Icepunch will give you the quick one against all those Dragons. I picked Aerial Ace over Zen Headbutt for the Heracross factor. Giving Heracross 4X weakness to Flying-Type moves, this will also cover Infernape. However I'm not sure if this will OHKO him, so if you want the OHKO on Infernape rather then Heracross you can chose ZH, however AA will take them both on rather then just one of them.</p>

<p>(Info taken from J.Kudo)</p>