How long does it take a fossil to form?

Very pretty; I like it, by the way.

I think you could get the thing identified from someone who knows simply from the video or some clear photos. (It might help to place a ruler next to it in a photo to give some certainty in scale.) Start at a natural history museum in your area and work outward from there if you’re not satisfied with what they tell you.

My understanding, without researching this closely, is that the fossilization process takes a very long time. That is, the organism has to be immobilized in mud or something like it, and die, and then the body’s tissues are gradually replaced with minerals that precipitate out of the water or other “containing medium” (such as mud). And that process can take many years—or at least it’s assumed to—I don’t know if anyone has been able to artificially create a fossil.

If you want to preserve the fossil you’ve got (assuming it is, and it sure seems to be a huge dragonfly, bigger than any that I’ve ever seen), then I’d recommend covering it with something that will prevent erosion and not trap acidic water on it, either.

Fossils can form very quickly, under the right conditions. A matter of years, I think.

That is an awfully large bug; you might take it someplace to be looked at.

Fossils can form quickly (relatively speaking) under the right conditions. That being said, dragonflies are one of the most ancient orders of insects- in fact they may be the oldest insect order- and have been around 400–500 million years. So it might be worthwhile taking your specimen to your local natural history museum!

Fossils can be anywhere from 10,000 years old to billions of years old. One of the most important ways to tell the age is to examine the rock itself and where it was mined. In my area the prevaiing fossils are 350 million year old brachiopods. (Cardiola, from the Devonian) The rock looks like limestone and is reasonably hard.
There are also fossils of mastodon bones that are only 12,000 years old but they are in soft soil and are easy to break.
The Erie Canal bed went through an area rich in Trilobites that are 450 million years old. Those are very hard.
Take the specimen to the museum or science center. They will gladly help identify what you have.

not really an answer but that is SOOOO cool.

You can make fossils in a single day: Take a fish, a leaf or the specimen of your choice, place it in wet concrete or plaster and let it harden. The impression left in the concrete or plaster is known as a fossil.

@noplacelefttohide definitely not a fossil.