Tanis is about 3 years old. She is the shortest of all the girls, has blue eyes, white skin, and she wears a plain white dress and wears a dark pink bow on her head, and the bandages on her head resemble a ponytail. She gave her Mummy Daddy a "Fright Light" shaped like a mummy case with a mummy figurine inside that gives off red beams out of it's eyes when it opens, "to brighten the darkest mummy case." Tanis also has a very similar voice as Darla Hood in the animated 1982 Little Rascals Cartoons from Hanna Barbera. (Her voice actor Patty Maloney uses Darla Hood's voice for Tanis)
Because she is so young, Tanis has a childlike personality, and is usually a very happy girl. She is also plucky and kind.