No, they weren't Na'vi. But let me start from the beginning.
The first part of the dream was pretty boring, actually. I was inside some building, skating, then I helped some people who were looking for some kind of gadget to prevent a baby's death (I know, it doesn't make sense; I didn't get that either).
Then I was outside the building, and the blue guys appeared. They walked side by side, maybe eight or more of them. And they had teeth. HUGE pointy teeth which made them look quite scary, like piranhas.
They didn't speak, but I knew their mission was to destroy our world! What to do? There was nobody by my side, so it was up to me to save the planet Earth.
I did something pretty weird, then. I asked Nature to help me! And then I had superpowers!! Plants grew from everywhere at my command, like some kind of green explosion. That was enough to discourage the blue invaders, but they got mad and came after ME.
I escaped flying, then I searched for some hiding place. No matter where I hid, though, the blue guys always found me and I had to fly away from them again. I finally reached some kind of forest. I found a hollow place in the grass and curled up there, covering myself with more grass (again, I used my fantastic superpowers).
Now I was safe. At least the evil blue guys couldn't see me anymore, but well, after a while I got pretty bored. I couldn't move or else I'd be detected, and there were some other people around, enjoying the sunny day at the forest. I noticed that some of them could see me when I blinked, so I asummed my eyes weren't covered with grass like the rest of my body. Then I was afraid someone would reveal my presence to the evil blue guys.
That annoyed me so much that I finally woke up.