9. The Bad Batch
This might be a bit of a stretch because The Bad Batch is getting its own show spinoff at some point, but what happened to these guys after the Clone Wars?
Did they have the same chips in their brains as all of their brothers? Did they wind up working for the Empire?
It would be fascinating to see the Bad Batch regardless if they ended up working with the Empire or not. These guys were way too good of soldiers and specialists to just be killed off at some point, so could they be the next ones tasked with pursuing the Child?
The Bad Batch were a defective group of Clone Troopers whose defects were of the positive variety. One has super-human strength, another has superior intelligence, another has outstanding combat skills, and another has sharp-shooting abilities.
Although they were a huge part of the initial plot in the final season of The Clone Wars, we never saw what their ultimate fate was after Order 66.
We will undoubtedly see these guys again, but without more backstory, it might be surprising to see them pop up in The Mandalorian.