Nico Robin is the archaeologist of the Straw Hat Pirates. She was originally introduced as the Vice President of Baroque Works known as Miss All Sunday before joining up with the Straw Hats. She is a tall, slender yet athletic woman with shoulder length black hair. Her eyes are blue in the anime with dark and wide pupils (brown eyes in the manga and the 10th movie), and she has a long, thin and defined nose. (Introduction Source: Wikia.com)
Here is a Nico cosplay from a Japanese cosplayer yuuna(ゆーな). Don't you think this cos is very similar to the original Nico? (Source: Cosplayers' Cure)