Emily Arched Hook-Tip is the alias of Holly Axolotl when she is in a Blood Market. As she is a Water Dweller and therefore unsafe in Blood Markets, she masquerades as a Mist Dweller when trading illegal goods.
Holly has only visited the North Island Blood Market three times in her life: once when buying a toothbrush, once when visiting a ghost, and once on her return from the War. During her first visit, she was captured and sapped for her blood. She masqueraded as Emily Arched Hook-Tip, a fifteen-year-old Mist Dweller who was in love with Tristan Wolf, her ally. She wore very light blue contact lenses, and, during her second visit, pinched her cheeks to give them a rosy glow. Her disguise would not fool someone who already knew her face, but that was not her goal. Her goal was just to have them believe that she was a Mist Dweller, and not a Water Dweller. During those times, Blood Markets were made for the use of Forest and Reserve Dwellers. Contrary to popular belief, Blood Markets were actually legal until August 2018 - Calvin Ring-Tailed Lemur had designed them as places to trade DNA that could not be found at Headquarters. Unfortunately, as the founders passed, the law bent and traders began acquiring substances illegally. He did account for the fact that most of the traders would be of dangerous Dwellings, and made it illegal to sap particular Dwellings within the Market, or act as if their bodies were up for trade. According to the law, it was morally wrong to "harvest the blood of a Runaway Kid who is of Peace, Sun, Surface, Shallow-Shore or Water, as they cannot protect themselves." The first three Dwellings are classified as "Prey", while the latter three are classified as "Safe". Holly was classified in the "Safe" group, which meant that it was indeed illegal for Kendrick and Bozek, two kidnappers, to take her blood or tears. Then there comes the crucial fact that she was wearing a disguise - a disguise supposed to make other people believe that she was a Mist Dweller. Arguably for the kidnappers' side, they could have believed that she was of Mist and legally took a small amount of her blood (sapping Mist Dwellers was and still is legal, as their bodies generate blood automatically).