Ariel Cap (born March 1, 2032 in Jerusalem, Israel) is one of the adoptive daughters of Marci and Matthew Cap. She and her vigintuplet siblings, Ben-Gurion, Even, Gil, Golda, Maor, Tzabar, Ronia, Netanya, Yonatan, Hadassa, Abrahem, Ananiah, Balfour, Ayalah, Navah, Yinon, Zivah, Hagar and Tzahala, were orphaned when their parents were killed in a car bombing
- Father: Matthew Cap
- Mother: Marci Cap
- Brothers: Ben-Gurion Cap, Even Cap, Maor Cap, Tzabar Cap, Yonatan Cap, Abrahem Cap, Ananiah Cap, Balfour Cap, Yinon Cap
- Sisters: Gil Cap, Golda Cap, Ronia Cap, Netanya Cap, Hadassa Cap, Ayalah Cap, Navah Cap, Zivah Cap, Hagar Cap, Tzahala Cap
- Her full name is Ariel Tasmia Cap
- She likes to play with a dreidel.
- She is made fun of by Dennis for having the same name as the heroine in the Disney movie, The Little Mermaid