Path of Exile‘s latest content update is filled with all kinds of beasties ready for you to hunt down and capture. There are nearly 300 critters, all located in Wraeclast, that can be captured and then used to create and augment items.

Known as the Bestiary Challenge League, this feature implements new mechanics to the game. Players will have around 250 regular beasts and 40 legendary ones to capture, completing their Bestiary and adding them to the Menagerie. The animals in the Menagerie can then be used in “Beastcrafting” — but you’ll have to make literal sacrifices to do this. In fact, you’ll have recipes requiring the sacrifice of combinations of beasts. So… Maybe don’t get too attached. You can read up on the system in Jason Winter’s preview.

In addition to the new Bestiary feature, this expansion also adds new end-game content, including the “toughest boss encounter in Path of Exile yet”. There are new gems, new unique items, and an Ascendancy Class Revamp.

The new expansion is available on PC starting today. Xbox One players can look forward to getting in on the action next week.