ON3i11
Skeletron Prime
There is probably a max number that the devs put in, but I'm sure you could tell the generator to fill the map with them.I was going to suggest the exact same thing. however, I would really like to know how many pyramids, living woods trees, etc., can theoretically be generated with the original ingame generator. the thing is, I would love to have a world with the maximum number of pyramids and so on, but it should still be a world that in theory, could have been a result of the original generator, too.