Most people are familiar with the movie The Predator, in which Special Forces soldier Quinn McKenna (actor Arnold Schwarzenegger) is stalked by an alien being who is able to cloak himself with a shimmering translucent appearance. The universe is sometimes stranger than movies. Would it surprise you that there are indeed people who have encountered strange creatures who had a similar translucent appearance. Sometimes they were even seen in their physical form before they became translucent. It can be quite unsettling to see the translucent appearance of an unknown creature, not to mention to see an alien being (although not looking like The Predator) turning on his translucent camouflage. We like to see the world and its inhabitants as physical beings that can be viewed at all times. It is not a comfortable idea that there are beings that can make themselves invisible and can roam around our neighborhood.
If you want to know more about these sightings, go to my article of Translucent Humanoid Beings.