Yaddle is a member of the same unnamed species as Yoda and Grogu. She was created for Star Wars: Episode I The Phantom Menace (1999), where she sits on the Jedi High Council and is never addressed by name in dialogue — she is identified only in the credits. Her puppet was operated by Phil Eason, and her design began as an Iain McCaig concept sketch for a young Yoda.
Twenty years of nothing, then two careers at once
For most of her existence Yaddle was a piece of set dressing. Two things changed that. The High Republic initiative put her in 382 BBY as the Jedi Master responsible for Initiates, fighting the Path of the Open Hand on Dalna at the massacre the fiction calls the Night of Sorrow. And the 2022 animated anthology Star Wars: Tales of the Jedi gave her a death: in the episode "The Sith Lord", she confronts Dooku, meets Darth Sidious, and is killed by her old colleague when she refuses to stay quiet.
Why it matters
Because it retroactively made the silent figure in the Council chamber the last person who might have stopped it. Dooku's fall in Tales of the Jedi is completed by killing her, and every subsequent viewing of The Phantom Menace now has that sitting in the frame.
Where to find her
The High Republic Phase II material, notably the events surrounding Dalna in 382 BBY; Tales of the Jedi (2022) on Disney+; and the Council scenes of Episodes I and II.