Niko

Niko is a young boy who lives in Freedonia, in Despicable Me 3.

History
Niko is first seen in the film during the cheese festival where little girls choose a boy to take a piece of cheese from his plate. Niko is the only boy who isn't chosen by any girl, causing him to get depressed.

As the Gru Family visits the island, Margo is forced by a sympathetic Lucy to take a bite of Niko's cheese during the Cheese Festival, to Niko's joy and causing him to develop feelings for her.

Niko visited Dru's Mansion and told Lucy that he came to the woman he loved and informed her of their new engagement. Margo turned up, and Niko graciously offered Margo his pig as a sign of their engagement, and his eternal, undying love. Clearly disturbed, Lucy rejects his offering and refutes the engagement, despite it being a tradition in his native country, which they were currently in, which was a highly disrespectful act. She sends him away, as Niko isn't surprised and stated he was foolish to think he had a chance with Margo, promising not to forget her and mopes away. Uncomfortable, Margo nervously says she won't forget him either.

A moment later, Niko returns along with his Mother and baby brother who, quite rightly, infuriated with Lucy's refusal to her Son and Margo's engagement. She cursed Margo and Lucy, to which Lucy assaults her, by grabbing her by the collar and yelling that she should never dare to curse Margo again (it is inferred that Lucy would kill this woman to "protect" Margo). The woman, fearing for her and her child's safety, walked away, with her heartbroken son crawling along with his Pig, as the Pig is a symbol for his lost love, and permanent solidarity

Personality
Niko appears to have low self esteem as he is frequently depressed during his screen time in the film and laments his appearance. Whilst he appears to be a nice boy, Niko comes on much too strong in his attempted engagement of Margo, embarrassing the girl who was not ready for such a relationship with someone she had just met and unfamiliar with the culture of Freedonia.

He is quite smitten with Margo and when she rejected, cried that a fat goblin like him had no chance with a goddess like her. Unlike his mother and brother who were angry, he still appeared forlorn when the family visited the door of the Gru family.