This Dragon is highly unpredictable, poisonous and has an exceptionally low melting point. But when the sun shines from the right angle, this liquid creature looks absolutely magnificent!
Mercury is a chemical element with the symbol Hg and atomic number 80. It is commonly known as quicksilver and was formerly named hydrargyrum. - Wikipedia
His second element is Sea, because Mercury is the only metal that is typically liquid at room temperature. Also, Mercury is the one of the two elements that are liquid in the periodic table (with the other one being Bromine).
The Chinese name for Mercury is literally translated as "water metal".
Even though it has Metal, it cannot learn metal attacks in the Training Center.
It is the second lowest gold producer after Sea Dragon.
Its body looks similar to that of a Flame Dragon or Cool Fire Dragon and it also has the same facial expression.