User blog comment:SilverHexxitFights/Which is Terraria's Hardest Boss?/@comment-24151017-20131111054633

I had so much trouble defeating planterra that I had to make an arena (Which I never do). Golem is very underpowered.

You have forgotten Dungeon Guardian, He counts as a boss if your letting the Paladin/Ice Golem although he would get all the votes which is why I presume he's not there