To get this awesome flail that totally outclasses the Ball O' Hurt , because we're all sick of that one by now you just have to collect Crimtane Ores and Tissue Samples from the Brain of Cthulhu and the Eye of Ctulhu. The Eye will actually drop Crimtane ore if your world is Crimson. The Brain only drops the Tissue Sample you need. They drop absurd amounts of ore and tissue so you'll have enough with just one kill! Earlygame this flail will serve you extremely well as it mauls alot of enemies with ease.