A Laetiporus Murrill mushroom called "Chicken of the woods" grows on a tree in a protected area of Bialowieza forest, the last primeval forest in Europe, near Bialowieza village, Poland May 30, 2016.Reuters

The search for aliens has been one of mankind's biggest quests. Now researchers state that there are in fact 'alien' creatures that live among us on Earth. These creatures cannot be classified as animal or plant because they have unique features which defy these classifications. So what are these creatures? 

One of them is the sea anemone. This is supposed to be an animal but the fact is they look like plants. In fact, its name is also derived from flowers. Sea anemones can also be found similar to humans but their anatomy is very unlike us. What life form are they then? In fact, sea anemones also have the incredible ability to repair their damaged hair cells.These are probbaly one of the few creatures that can repair dmage to its body!

Another creature is the sea slug. These cannot be called plants or animals as they  thrive on chloroplasts from algae and seem to adehere to veganism. So are they the first creatures to ever discover veganism?

Algae, which we think of as a plant, has always been defined as single cell lifeform but then they don't have roots or leaves. Now isn't that a mystery?

We all think of mushrooms as being part of the plant species but hold on. They are not. In fact, researchers say they are closer to animals! Mushrooms don't use photosynthesis but they get their energy from other organisms.

sea anemone
A family of Clown fish hides among the anemone on the shallow sandbanks of the Ligitan Reefs.Reuters

Did you know that the honey fungus, Armillaria, can grow to cover around nine square kilometres of forest, weigh up to 35,000 tons and even live up to 2,400 years? Perhaps, no other creature - plant or animal - can live this long on Earth at this point.