Speaking on Tatooine Sons: A Star Wars Podcast, Hamill said that before knowing Leia was his character’s sister he suggested to the Star Wars Boss that the jetpack-wearing bounty hunter introduced in Empire Strikes Back could have birthed Luke.
“I have always been more than willing to generously share my many, many terrible ideas in the off-chance we might stumble across one that could actually be useful,” he further explained on Twitter. “At the time, I didn’t even know Leia was my sister”.
Hamill also suggested that Fett could have been a double agent, a secret rebel hero who could be unveiled in Episode VI: Return of the Jedi. Sure, this wouldn’t explain how Vader couldn’t sense the mother to his children was close, but it would undoubtedly be a surprise.
I once suggested it to George as the only way we could top Vader being my father. I envisioned her as a double-agent working clandestinely for the Rebels. SPOILER ALERT: He didn't like my idea.
Then there was the time I pitched Boba Fett as Luke's mother. I have always been more than willing to generously share my many, many terrible ideas in the off-chance we might stumble across one that could actually be useful. At the time, I didn't even know Leia was my sister. https://t.co/nurhFZZS01
Sadly, Fett was never unveiled as a rebel operative and Hamill’s pitch was rejected. However, Fett still enjoyed a role in Return of the Jedi: nudged into the Sarlacc pit by a near-blind Han Solo. That’s just as good a part, right guys?