It is her most precious item.
Nepeta, Terezi, Aradia, and Kanaya was: http://ryokothegreat.tumblr.com/
Equius, Sollux, Gamzee, and Karkat was me: http://thatorangealien.tumblr.com/
Original comic found here: http://sandyhams.tumblr.com/post/13232027836/i-had-to-sorry
