>>11206809Boba Fett started off a little bit like a cryptid. He made his first appearance at a parade in California in 1978. No name, no backstory, just a guy in really cool looking armour that seems to be teamed up with Vader. Then you have the Holiday Special which reveals him as a villain, then you have him shown to the wider world in Empire where he clearly has not only history with Vader, but that Vader respects him enough that he gives him a warning for previous actions "No disintegrations" when this film has shown that Vader usually outright kills people that displease him. So clearly Fett is worth keeping around.
Fett had been making appearances before his major debut in Empire, but the main this is his toy was on shelves for a year before Empire came out. So kids were seeing this awesome looking character who was mysterious and worked with Vader. It's the perfect way to cement a character in kid's imagination.
