death, fire, WWIII, the apocalypse, poison, random dude crashing his car into the wall, jason coming in with a chainsaw, mashy spike plates, the list is endless, really.
I would have to say..... dead bushes. BTW for all of you hating on sponges, if you want a distinct block for a filler that you know "only destroy the sponges" to empty your submarine or whatever, sponges can be pretty usefull.
I discovered that dropoffs were not good for your health in 1.2 beta, and i spam clicked the tree for 10 minutes IRL until one of my friends told me you had to hold the button, And I discovered that creepers were not to be invited to tea parties