Monster Meat

This drops off ordinary evil biome enemies, and the odds are bad enough that nobody picks one up during a normal run. If you want it, build a spawn farm in the Corruption or the Crimson and let it grind while you do something else. A Constant world improves the odds by a wide margin, which is the only realistic way to chase it on purpose.

Statue-spawned Eaters of Souls are the worst source there is. Statue enemies carry a heavy drop penalty on top of an already tiny chance, and the result is the longest odds attached to any item in the game. Do not build that farm.

You get a Pig Man trotting along behind you. Jump or outrun it and instead of sprinting it opens an umbrella and floats after you. The whole item is a nod to Don't Starve, from the tooltip wording down to the umbrella being stitched out of pig hide.