Nelliel Tu Oderschvank

Neliel Tu Oderschvank, commonly known as Nel Tu, is a good-natured, child-like arrancar when first introduced. The remains of her hollow mask make up a cartoonish skull on the top of her head. Nel and her companions believe Soul Reapers, not hollows, to be evil, and as such are afraid of them. In spite of this, she develops an attachment to Ichigo Kurosaki and starts following him around after her introduction. She often mispronounces Ichigo's name as 'Itsygo' due to her lisping, and she is a self-proclaimed masochist.

(Source: Wikipedia)