Here is how to get it in a couple of minutes. I got it at my first try using this strategy.
1. Start a multi-player game of Escalation. Make sure you start out in a lobby. Don't join a game already in progress. You might need to host a game. Have one other player. Having more than one is ok but it's easier with just one other player. It won't work if you are alone, though. You might want to inform the other player what you are about to do.
2. Make sure you start out as the Autobots. Any Autobot will do. I did it with Optimus Prime.
3. As the game starts, before the first wave, immediately melee an explosive barrel or two. You want to reduce you health until you have only one bar left.
4. Quickly run over to another explosive barrel. Don't drive, you might trigger it by accident. Ideally it should be one in a central, exposed location.
5. As the first wave starts spiders will spawn and swarm around you. Don't attack. Just stand next to the barrel and wait while they eat down your health. Keep your gun loaded. Keep your character pointed in the direction of the barrel.
6. Wait until you run out of health and get downed. As soon as this happens, fire at the barrel until it explodes. The explosion should wipe out the swarm of spiders. You should get the achievement.