Sap: Mistlands only, and it regrows
Sap comes from Ancient Roots in the Mistlands, and you cannot harvest it by hand — it needs a Sap Extractor built on the root itself.
The extractor costs Yggdrasil wood x10, Black metal x5 and one Dvergr extractor (from Dvergr component crates), and it must be placed within range of a Workbench. It has 100 durability, takes rain damage, and is immune to Poison, Spirit, Chop and Pickaxe.
Two properties make sap worth setting up early: it weighs only 0.2 with a 50 stack, and it teleports — so unlike ore, you can carry it through a portal. It is also renewable, because every Ancient Root refills over time rather than depleting.
Its main use is refining into Refined eitr, which is the gate on Mistlands magic. That is why the extractor is usually the first Mistlands structure people build.
Ymir flesh: 120 coins, and not before The Elder
Ymir flesh is not found, farmed or dropped. Haldor sells it for 120 coins, and only after you have defeated The Elder.
That gating catches people out: finding Haldor early does not mean seeing his full stock. If Ymir flesh is not in his list, you have not killed the second boss yet.
It weighs 0.3 with a 50 stack and teleports, so there is no logistics problem. Its uses are narrow — exactly two recipes: Frostner and the Iron sledge. One purchase covers both.
Chickens: 30 minutes next to a fire
Chickens only exist as hatched eggs. Put an Egg beside a fire or heat source and wait 30 minutes; the egg must read as warm when you hover over it, or it will never hatch.
A chicken has 10 health, does no damage, and drops Feathers and Chicken meat. It is the juvenile stage of the Hen, so a hatched egg is a long-term feathers source rather than a one-off.
Because it needs a heat source and 30 real minutes, the practical setup is a dedicated breeding pen with a brazier rather than a campfire you keep refuelling.
Onions: three seeds, roughly 70–80 minutes
Onions grow from Onion seeds, three per crop, in the Meadows, Black Forest and Plains. Grow time is 4000–5000 seconds — about 67 to 83 minutes.
Each onion gives 13 health and 40 stamina over 900 seconds, which is decent stamina for a crop that also feeds taming and cooking recipes. It stacks to 50 and teleports, so bulk storage is not an issue.
The bottleneck is the seed supply rather than the growing time — a single crop consumes three seeds, so you need a seed stock before onions become a reliable food source.