Posted May 7th 2006, expanded later
Looks like we've got a third megabattle on our hands, and in level 3 of all places! It takes place in the dustbowl area, featuring a rocky bridge over a bowl-like depression. Amazingly you can have up to 50 enemies there, made up from the usuals plus enemies from earlier on, who you've encouraged along. They'll all chase you around, which lets you lead them to good places to defend from, do a progressive defence on the move, or whatever. It's great for chain reactions and general mayhem, and you can have some hilarious fun with up to 32 Grunts chasing around after you, surely the biggest gaggle in the game. You should see those critters swarm! If you want a megabattle that makes you laugh, this is it.
The first page covers setting up, including a quick-start basic plan to get you going, and a much more detailed plan you can delve into later if you want to get more refined. There are a few extra set-up tips after that, then some general battle advice and a bunch of specific battle plans you can try out. I've also included a page on how this megabattle came about.