A native of the planet Athos and member of John Sheppard's team based in the city of Atlantis, and once the proud leader of the Athosians. Teyla is cautious, and must get to know someone before trusting them. She found a special connection with John Sheppard upon meeting the humans of Earth for the very first time.
Teyla and her people use the Stargate to visit many worlds in the Pegasus Galaxy, and she had never before encountered a culture that had not heard of the Wraith -- a terrifying enemy that has oppressed her people for generations, harvesting them to feed upon their life-force. Teyla is a strong and capable warrior, and a confident leader -- though she was reluctant to say goodbye to her people to remain in Atlantis with Sheppard's reconnaissance team.
While returning with Sheppard from a hidden sanctuary where her ancestors once hid from the Wraith, Teyla herself was kidnapped in a culling beam and taken to the Wraith hive ship on the Wraith homeworld. She was later rescued by Sheppard and Lieutenant Aiden Ford.
Teyla returned to Atlantis and met even more humans from the Tau'ri, eventually establishing a colony there for her people. She dedicated her services to helping seek out new allies for the humans now based in the Pegasus Galaxy, and her experience with other cultures makes her an ideal guide for the humans from Earth. Teyla also possesses an extra-sensory awareness of the Wraith when they are near. She has struggled with her decision to leave her people, but believes that her work with the humans on Atlantis in the fight against the Wraith is the best thing she can do for the Athosians now.
Teyla's father was named Tagan. Due to experimentation by a rogue Wraith scientist she possesses a small amount of Wraith DNA, which gives her the ability both to sense the presence of the Wraith and, with a great deal of concentration, to telepathically link with the Wraith hive mind and even individual Wraith -- though the experience usually overpowers her, leaving her vulnerable to Wraith control.
After Teyla conceived a child with her Athosian companion Kanaan she found herself and her child (eventually born "Torren John Emmagan") targeted by the Wraith hybrid Michael. She was rescued by her team after Michael captured her and experimented on her, and when Michael and his hybrids later invaded Atlantis to abduct her child she fought and killed Michael.
Rising, Part 1 - Teyla is introduced to the humans of Earth when they visit her home world of Athos. When the Wraith attack, she is taken in the culling.
Rising, Part 2 - Having been rescued from the Wraith, Teyla joins the new team in Atlantis and vows to help them find allies in the Pegasus Galaxy.
Suspicion - After the recon team continues to meet the Wraith again and again on missions, Weir suspects a traitor in their midst -- and Teyla is the chief suspect. When the Athosians move to the nearby continent, Teyla makes the hard decision to leave them.
The Gift - Plagued by terrifying nightmares, Teyla recalls a time when she and her father were captured by the Wraith and subjected to disturbing experiments -- and discovers that she has some Wraith DNA herself.
Critical Mass - The woman Teyla considers to be her last living relative, Charin, dies, and she honors her memory by performing the Ring Ceremony over her body.
Michael - Teyla helps a young man work through his memory loss, putting herself in harm's way when he realizes that he is a Wraith who has been turned human.
Submersion - When the team finds a Wraith Queen inside a facility at the ocean's floor, Teyla tries to telepathically access her mind -- only to be taken over by the powerful Queen.
Vengeance - Teyla is briefly captured by Michael, who has become a Wraith again and is conducting his own experiments.
Missing - Teyla takes Dr. Keller to visit her people on New Athos, only to find that they have vanished and may all be dead. She also tells Keller about Kanaan, an Athosian man with whom she has kindled a romantic relationship.
The Seer - Teyla seeks help from a renowned prophet, who tells her that the Athosians are alive. He also knows that she is pregnant.
Be All My Sins Remember'd - Teyla is involuntarily pulled from active duty after Colonel Sheppard learns that she is pregnant.
The Kindred, Part 1 - Led by a dream of her lover Kanaan, Teyla goes offworld in search of the lost Athosians ... and is kidnapped by Michael.
The Kindred, Part 2 - Michael hints at the plans he has for Teyla, using the secrets held by her child to perfect his army of hybrids. The team mounts a rescue operation, but fails to save her.
The Last Man - In an alternate future, John learns that Michael killed Teyla after her baby was born -- and returns to his own time with intelligence on locating her.
Search and Rescue - Teyla has her baby on board Michael's hive ship, and escapes with help from her team and Kanaan. She names him Torren.
The Queen - Teyla undergoes surgery to transform her into a Wraith queen in order to help Todd negotiate for the implementation of Dr. Keller's gene therapy.
The Prodigal - Michael infiltrates Atlantis and holds Teyla hostage, with the intention of taking her child. But when the team gains the upper hand, Teyla sends her old foe falling off the command tower to his death.