Locker
Every animal you have ever built, kept forever. The ones outlined in amber are what Start Best Animals would put in your five, and each says why it was picked — strongest, healthiest, or the only one of its category.
Shop
Ordinary parts you can win in a fight. Mutated parts you can only buy here — and every mutation costs you something as well as money, so a heavily mutated animal is powerful and fragile at the same time. The shelf changes every 10 minutes on its own, or pay to shuffle it early if nothing here is worth saving for.
Field Guide
Every part comes from something. Collect a part and its page fills in — where it lives, what it eats, and what the person who wrote this book thought of it. The real animals are real; the rest are reported.