I guess that you misunderstand what typecasted means. It doesn't mean that someone else can't play your role. It means that once you develop an iconic character, everyone will always think of that character, no matter what role you're now trying to play. :D
I gave examples of actors who played Batman without people now seeing them as nothing else, showing that, "Once you're Batman, it's hard to see you as anything else," is untrue.
The thing with Adam West, Jerry Mathers, Ken Osmond et al is that no one had heard of them before or after those roles.
Eddie Haskell was my favourite.I never thought of him as a pest. He was very funny. Lumpy was the one I never liked. He was always getting Wally into trouble and he got on my nerves.
I'm a huge Leave it to Beaver fan and recently got my five-year-old into the show as well. We had been watching episodes daily. So sad! I had just listened to an interview with Ken Osmond and he talked about having nerve problems in his legs and being unable to walk unassisted. There has been no official cause of death announced yet but they say he had respiratory issues. It's too bad; at 76 he was relatively young. He was always slim and looked healthy to me. I'm very bummed about this.
I'm bummed too. He was a LAPD motorcycle cop. He almost died in 1980, he was shot 3 times by a car thief. Imagine getting pulled over by Eddie Haskell for speeding! I'd love to give him the "Gee officer, I had no idea I was speeding. Perhaps my speedometer is malfunctioning? I should have that checked immediately. Thank you for bringing this to my attention. By the way, I'm a huge supporter of law enforcement, you guys don't get the appreciation that you deserve. You really look good in that uniform".