Amoeba (plural = amoebae) is a well known genus of unicellular organism, a protist. One of its most common species, the Amoeba Proteus, is about 0.2 to 0.3 mm large. The amoeba was first discovered by August Von Rosenhof in 1757. It is a genus of protozoa that moves with "false feet", called pseudopodia.