Rakatan
The Rakatans, also called the Rakata, were an ancient amphibious humanoid species from the planet Lehon. They famously ruled the so-called Infinite Empire. Legends say that they were the originators of hyperspace technology. In ancient galactic history, the Rakatans launched an invasion, but a subsequent uprising successfully pushed them back. A Kuati Signet, featuring a blue kyber crystal, was created to remember this rebellion. It is said that the Rakatan species eventually died out due to the corrupting influence of the dark side of the Force. They share their designation with mysterious artifacts referred to as Rakatan wraith boxes.
Behind the scenes
Canon and origins

The Rakatans were first acknowledged within the new Star Wars canon inside the forty-fifth issue of the De Agostini magazine titled Star Wars: Build the Millennium Falcon, although this was only in its German version. The species was initially conceived in Star Wars Legends within the 2003 video game, Star Wars: Knights of the Old Republic. In that game, the Rakata are depicted as the remnants of a once vast, galaxy-spanning empire. They had conquered, governed, and decimated other species through the power of the dark side of the Force. The Force was the source of power for the Rakatans' hyperspace technology.
Inconsistencies
Star Wars series

In the forty-eighth issue of the 2015 Star Wars comic book series, published by Marvel Comics on May 23, 2018, with writing by Kieron Gillen and pencils by Salvador Larroca, a Mon Calamari was mistakenly shown as a Rakatan.
Poe Dameron series

Similarly, in the seventh issue of the 2016 Star Wars: Poe Dameron comic book series, published by Marvel Comics on October 26, 2016, with writing by Charles Soule and pencils by Angel Unzueta, an unnamed "thug", referred to as "generic alien extra #3457" and described by Story Group's Matt Martin on Twitter as a "mysterious background guy", also bore a resemblance to the Rakatans, although their species was not specified.