Destroy All Humans!

Here is my 100% Achievement guide and full walkthrough so you don't miss a thing.

This too is technically unmissable.
Furon probes look like little mechanical robots just floating in mid air. (Very hard to miss)
All we need to do is collect one.

There are loads about so you shouldn't miss one, but what they are, are basically the DNA for upgrades we need.

If you need one, go to free roam turnipseed Farm.
Immediately to your right when you spawn you'll see a small hut/house.. there is one floating there

Go to 24:45 in my part 1 video to see where and how to unlock this

Hope this helps!

Part 1

Part 2