Beastcrafting is a new mechanic that was introduced in Path of Exile's Bestiary League. Throughout the Bestiary League, players will be able to captures Beasts and will occasionally captured Yellow Skull and Red Skull beasts which are beasts that have a red mod to them. The Yellow Skull beasts have one red mod while the Red Skulls have two.
While players capture more beasts, they'll discover more and more Beastcrafting recipes. Collectors of poe orbs can check what recipes they have and what monsters are under their possession by pressing H and switching to the Bestiary tab.
Players can access Beastcrafting by visiting The Menagerie through any town or Einhar Frey. While at The Menagerie, players can view all of the beasts they have captured in their own respective habitat, Caverns, Depths, Sands and Wilds.
In order to craft the new recipes, players must use the Blood Altar and choose the recipe they want to do. Players will have to sacrifice certain beasts to the Blood Altar that satisfies the recipe then proceed to fight the beasts sacrificed. Note that the item level of the recipes that given an item will be based on the beast that is first sacrificed. Also that if you fail to defeat the beasts at the Blood Altar, they will despawn and you'll have to recaptured them again. So, it's more favorable for players to make every beasts except for the first one as weak as possible.
With Beastcrafting players can sacrifice the Red Skull beasts or the legendary beasts to make random unique poe items or modify items such as adding mods to a rare map, coloring an item's sockets or linking item sockets. Also note that high tier beasts can be substituted for lower beast such as a rare beast can be substituted for a magic beast in a beastcrafting recipe.
The most rare of the Beastcrafting recipes are the ones that open a portal to the Spirit Realm. There are a total of 4 Spirit Realms, each containing one of the first beasts. The 4 first beasts are. Saqawal, First of the Sky; Craiceann, First of the Deep; Fenumus, First of the Night; Farrul, First of the Plains.
The difficulty of the beasts are also in this order as the map level of the portals are 70, 74, 77, and 80. The red skull beasts required to conjure up one of these portals to the Spirit Beasts are very rare. While in the Spirit Realm, players will have to fight 3 unique beast themed after the Spirit Beast before players have a chance of fighting one of the first beasts. Note that the beasts required to summon the portal is very rare and the captured Spirit Beasts allows players to craft Spirit Beast exclusive modifications to existing items.