my favorite main charecter is finn jake is my second and out of my favorite extra charecters starchy the grave digger and pepper mint butler are my two favorites and my two favorite one hit wonders are me-mow and lord monacromacorn (one hit wonder means that they were only in one special episode)

Do you know that adventure time theme was based on a post-apocalyptic setting. Why do you think they called it the mushroom war because the nuclear clouds made a mushroom formation. Thats why when Finn and Jake are playing Hide and Seek, ("Cloud Hunt") Finn sings a song that goes "Over the mountain the ominous cloud, coming to cover the land in a shroud, Hide in a busshel, a basement, or cave, but when the Cloud comes a' hunting, no one is safe! Thats why at the start of the theme song it shows this picture.

Note: that's why you can see the nuclear bombs, waste, skeletons, weapons and etc.