Poo

Eat something, sit on a Toilet, wait. Any tier of the well fed buff qualifies, the wait averages about ten seconds, and the buff is consumed the moment it happens. How much you get is tied to how much buff duration was left, so sit down immediately after eating rather than eating and wandering off to mine. The blocks cannot be picked up for a second or two after they appear.

There are two levers. The tipsy debuff roughly triples the rate, so a drink first cuts the sitting around considerably. Negative luck raises the yield, which is the one situation in the game where you want to be unlucky on purpose: a Pretty Mirror, a Stink Potion, a Raven Feather and a Wilted Clover together give most attempts a bonus multiplier, and killing a Ladybug or a Gold Ladybug drives luck lower still for a few minutes. Start from the longest lasting food you own, something like a Golden Delight, for the biggest single haul.

It generates naturally in Truck stop worlds, and Jungle Mimics drop it in Celebration Mk 10 worlds, so on those seeds you can skip the toilet routine entirely.

Fertilizer. That is the reason anyone farms it. Fertilizer turns a modest tree plot into a real wood supply and does the same for gem trees and stone, especially alongside an Axe of Regrowth or an Axearang, and Infused Fertilizer pushes the yields further again. Past that it feeds an Extractinator or the Chlorophyte version for dirt and the basic grass seeds, and it crafts into a Poo Boulder.

• Landing on it cancels fall damage outright. A layer at the bottom of a hellevator frees up an accessory slot for every trip down.
• Standing on it hands you a debuff, and placed piles spawn flies that multiply with the size of the stack, so keep it away from anywhere you spend time.
• Echo Coating hides the block but not the flies, so an invisible pile still buzzes.
• The tile id is 666, which was either a coincidence or the developers enjoying themselves.