Answer:
impalpable
Intangible.
There is no proof that aliens exist. I believe there is no such thing as aliens. Has anyone seen an alien ship? Has anyone seen an alien? No.
delta
married, how are you, your name again, kids, what do you do
presidents in god we trust date denomination
Well.... you can't really prove something doesn't exist, you can only prove it does. But, nobody has found or seen a pikmin outside the game.
Well a Kraken is a mythological creature, so there never was a first sighting of something that didn't exist. But it was seen in Pirate's of the Caribbean ;)
Actualization is the concept of making something existent in reality.
Unreal means something that doesn't exist, cannot be heard,smelled,tasted,felt, or seen. Something Unreal, is simply fake.
Because he doesn't exist.
Music or sound is something that can be heard but not seen.
Yes. they exist but rarely seen same as the deadly serpent an nightmare.