The elf who had no place whatsoever in the world of Middle Earth is the red headed Captain of the Guard Tauriel. She was a completely useless character that should not have had her own storyline. If she had just been a back round character then I would have been fine with her addition. Instead the writers made a love triangle with Kili, her and Legolas. This was a waste of time and took the story away from the main character Bilbo.
Now the whole love story was just terrible. Elves and dwarves do not like each other and have never had any sort of love story. Tauriel some how falls in love with a dwarf that she just met and who told her that “he could have anything down his trousers”. Wow, that would make any woman fall in love wouldn’t it. She then decides to forsake her kingdom to go save her supposed love and tricks Legolas into helping her by saying some crap about how they are apart of the world. She just wants to save her little boyfriend. Also, she abandons Legolas to fight the orcs so she can save Kili. This is just some crap they had to throw in that looks like how Arwen helped Frodo. The love story tears the last movie apart. Fili and Kili were suppose to die defending their Uncle which is the most honorable thing that they could do. Unfortunately they decided that Kili should die protecting Tauril instead and lets not mention how Fili just dies right away so we have time for this.
All in all she was a terrible character and really had no place in the movies at all. She is a disgrace to all things Middle Earth.