Animal Pen (like a prison but for creatures and creature blood)
Would be nice to have a new mechanic to "wrangle" animals inside a trap in your base, so that you can have now an animal you need to feed to drain blood from.
Creature blood is pretty good in some situations.
Maybe you can also capture sheep for wool production as well, and cows for a lot of blood essence farming (cattle are big and have tons of blood).
Each animal will have a different diet. Herbivores should eat fiber. Wolves should eat rats and hearts.