Another easy way of getting it is to start a co-op game for the campaign and get a friend to help you. Go to chapter VII and select part 3 "Megatron's Ambush." The first group you get attacked by is a small group of cars clones. Take some damage and beat them and then Megatron will start talking again. Once he shuts up, groups of spiders will attack. Here is where you let them take you down and as long as your friend is close the spiders won't scurry too far. Take your shots and voila, you have the achievement.
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