- "We will stand with you."
Along with Zafrina and Kachiri, Senna is a member of the Amazon coven, which reside in the South American rainforests, where most vampires never visit due to its scarce human population. Senna is described as very quiet, sticking close to Zafrina all the time.
Senna was best friends with Zafrina and Kachiri since childhood. They were all from the same tribe in the South American wetlands. When Kachiri changed into a vampire, she went missing for a few years. She returned to find Senna and Zafrina as soon as she learned to control her urges and changed them into vampires. They have been together ever since, hunting along the fringes of the Pantanal, only interacting with humans when hunting.
- Main article: Breaking Dawn
Senna makes her first appearance when Jasper Hale and Alice Cullen seek them out in South America. They tell them that their family is in danger and needs their help, but don't give much details. They then send Zafrina and Senna to Forks while taking their "sister" Kachiri on a quest of their own.
Upon arriving in town, she and Zafrina hear the entire story, and both agree to witness for the Cullens against the Volturi's accusation. She never leaves Zafrina's side during her time in Forks, and mainly observes everything that is happening in her surroundings.
During the confrontation, Jasper, Alice and Kachiri arrive with two prominent witnesses to prevent the battle from starting. After the problem was resolved peacefully, she returned to the rainforest with her sisters.
Unlike in the books, Senna seems to have a talking role in the movie.
Similarly to her sisters, Zafrina and Kachiri, Senna is dark-skinned and very long-bodied with wild dark hair, and wears nothing but animal skins. She also tends to wear her long black hair in a braid. As a non-vegetarian, her eyes are generally burgundy. She, along with her coven mates, are shown to be feral in appearance.
In Breaking Dawn, Bella Cullen describes Senna and Zafrina as two pieces of an organ; Zafrina just happens to be the mouthpiece.