She is one of Milhouse's cousins from the Netherlands. In her debut episode, she smokes e-cigarettes and sparked a "romantic" interest in Bart.
Annika has long blue hair and blue eyebrows. She wears a pink shirt, a purple jumper over her shirt, gray leggings, and fuchsia and white colored sneakers. She also wears several earrings and a necklace with a pink pearl.