If you aren't familiar and you want some additional information, here ya go!

Vesemir of Kaer Morhen was the oldest and most experienced witcher at Kaer Morhen in the 13th century and acted as a father figure to Geralt and the other witchers. Like many of the other witchers, he spent each winter in the fortress and set out on the path when spring arrived.

He is the only one of the old witchers to survive the assault on Kaer Morhen, left for dead among the corpses of his fellows. However, as he was only a fencing instructor, he didn't possess the knowledge necessary to create new mutagens in order to mutate more boys into witchers.

I don't know about you, but I'm sold! I think Hamill would be great in the role! The Witcher chronicles monster hunters who, with training and body modification, develop supernatural abilities at a young age to battle deadly beasts. Executive producers Sean Daniel and Jason Brown previously released the following statement offering some additional insight into the story:

“The Witcher stories follow an unconventional family that comes together to fight for truth in a dangerous world. The characters are original, funny and constantly surprising and we can’t wait to bring them to life at Netflix, the perfect home for innovative storytelling.”

It would be so cool if Hamill actually got cast in this role. I can't wait to see what becomes of this series.