Be, feel, look, taste, etc. like nothing on earth
Definition 1 of 2
Pro Tip 1/3Context Matters
Understand the situation to get if it's praise or sarcasm since 'like nothing on earth' can imply both uniqueness and weirdness. 
His singing voice is like nothing on earth — could be good or bad.
Pro Tip 2/3Unusual Things
Use this phrase to describe something that stands out as very different and not typical. 
That sculpture looks like nothing on earth; I've never seen anything like it!
Pro Tip 3/3Not Always Positive
Remember that 'like nothing on earth' may not always mean it's a good thing. It can express negative surprise. 
He arrived in an outfit like nothing on earth, and it was not a compliment.