Ok, I don't have a ton of experience with Kings in captivity (though I've been observing and catching Eastern's all my life). The only other King I've kept for any length of time was a Mole King, and it was a very timid snake compared to Easterns and the MBK I have currently.
I have a 2.5 year old female MBK that I picked up at a show for a very reasonable price, and she is a perfect captive. She always eats, sheds easily, and doesn't strike or musk. I've heard they can be occasionally musky, but not this one. She's a beautiful little snake that I very much enjoy because she is (knock on wood) trouble free. I've also noticed that she is quite inquisitive, but I think that's because she seems to be nearly always hungry. She acts like she would eat until she burst, so I limit her feeding to prevent her from getting too chunky.
Here're a couple pics...


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Lora