Alisa Southerncross

Alisa is an undead being / toy doll who feasts on aliens to gain humanity. Her adoptive father, Nevula, is the black alien who is trying to give Alisa humanity. She befriends the Keroro Platoon after Fuyuki protects her despite what she had done to them in Episode 133. In the manga, she only captures aliens and imprisons them in a box, referring to them as the "Dark Race", but is stopped after her father is attacked by Angol Mois.

Source: Wikipedia.org