The Trivia section names the origins of her Name as a spanish and dutch amalgamation which is completely wrong.
Leonhart also written as Leonhardt or Leonhard is a Old High German name that can be used as surname aswell as a Last name and is comprised from Old High German le(w)o („Lion“) and the Old High German harti („tough, bold, brave“). The english language equivalent is Leonard.
The Article should please be edited to correct this mistake.
So you should go to all episodes where Eren's a Titan and go to the character list and change Mysterious Titan, to Attack Titan. because you're wrong with the idea that the Attack Titan's true name has not been reveled yet, Because It has been reveled in the Anime