Coleman Kcaj was a member of the Jedi High Council and appeared in several episodes of The Clone Wars.
The first and most obvious Jedi corpse in Fortress Inquisitorius is that of Tera Sinube, an elderly Cosian who appeared in The Clone Wars as a friend and mentor to Ahsoka Tano. One Jedi from Star Wars: The Clone Wars is shown among the corpses that the Empire preserved for sinister purposes.
The Empire used the bodies of most Jedi who were dead by the events of the original trilogy.
While the only identifiable Jedi corpse at Fortress Inquisitorius is Tera Sinube, the Obi-Wan Kenobi scene also shows numerous other bodies, from an Ongree to several humanoids, and even a young Jediling. Vos, who is a friend of Obi-Wan, would be shown as a corpse among other dead Jedi without at least getting an emotional response from Obi-Wan. The number of Jedi survivors in both continuities is small, considering that around 10,000 Jedi were part of the Jedi Order before the coup.
In the fourth episode of Obi-Wan Kenobi, there is a scene where many Jedi corpses are preserved in Fortress Inquisitorius, with one being a familiar Jedi to Star Wars fans.
A background Jedi corpse resembles Mace Windu, leading viewers to believe that the legendary Jedi Master's body was recovered following his tragic death in Star Wars: Episode III - Revenge of the Sith and preserved within the Inquisitors' headquarters. The Jedi Order was nearly wiped out by the events of the original Star Wars trilogy because of the fascist rule of the Galactic Empire. Jedi survivors abandoned the Jedi way and lived normal lives during the Empire's reign, tragically trading their Jedi status for the sake of survival.
The Mandalorian believes that the blood of powerful Force-sensitives could be used to create Force-sensitive strand-casts, such as Snoke, or the resurrection of Emperor Palpatine. Jedi were corrupted to the dark side through torture by the Empire, as well as the Sith Order and Inquisitor Program. While only the corpse of Jedi Master Tera Sinube is identifiable, the other bodies have led to speculation over which other Jedi were killed and preserved by the Empire.
There are many Jedi Purge survivors in both the canon and Legends continuity, which seems to cheapen George Lucas' vision of Order 66 and the purge leaving only Obi-Wan and Yoda alive. The Jedi corpses in Fortress Inquisitorius show the body of Sinube, who was killed at some point during the Jedi Purge. The purpose of the Inquisitors preserving Jedi corpses is unclear in the episode, but other Star Wars properties imply their potential uses. In the first season of Star Wars Rebels, the Grand Inquisitor uses the corpse of a Jedi to lure them into a trap.
The youngling was killed during Darth Vader's attack on the Jedi Temple. Mace Windu was a major Jedi character, so he wouldn't have shown his body to the other Jedi so nonchalantly. Mace Windu's potential survival is a popular theory among some viewers, making it highly unlikely that a brief background appearance as a corpse would be how the Star Wars franchise debunks this theory. Sinube was a kindly Jedi with a quirky sense of humor who was happy to help Tano recover her weapon and impart lessons of patience and deduction to the padawan. Quinlan Vos was mentioned in a previous episode of Obi-Wan Kenobi. The lightsaber and body of Mace Windu were most likely lost in the streets.