Phasma was a Captain with the First Order in The Force Awakens and The Last Jedi. Gwendoline Christie played her in The Force Awakens and The Last Jedi and will voice her in the upcoming animated series Star Wars: Resistance.
You can learn about Phasma’s backstory in the novel Phasma written by Delilah Dawson. She also had her own 4-part comic mini-series Captain Phasma written by Kelly Thompson.
Other places you can find Phasma include some issues of the Poe Dameron comic series, the Star Wars Adventures story “Pest Control”, and the novel Before the Awakening.
Here’s the deleted scene with Phasma and Finn from The Last Jedi.
Check out the entire list of women in 365 Days of Star Wars Women in the Women in Star Wars Index. It includes highlights from each post plus notes which posts include new 365 interviews with actresses, writers, artists, and more.