6. Leafy Seadragon
It is one of the shocking weirdest creatures which a person cannot see or find even if it is near him/her because it is similar to floating weed. The outgrowths of its body make it look like weed. It contains transparent fins which a person cannot see because they are invisible even when the creature is moving in the water. The only thing by which a person can see the creature moving near him/her is by the moving eyes of this animal. It also changes the color but it depends on the food intake and the location where it is living.