S Tier

Basic (Tier 1)Starter poolBasic is the largest tier (≈10 animals by inference) and the easiest to complete. Hatch out the Index early so plot slots are never empty.Beyond (Tier 9)Endgame chaseBeyond is the rarest tier (≈2 animals by inference) and the Index completion goal. At default priors, ≈1,000 Standard rolls per Beyond animal; ≈14 Premium-only rolls.

A Tier

Legendary (Tier 7)Premium targetLegendary is the first tier where Premium Lucky Blocks materially outperform Standard rolls. The Index ETA tool surfaces Premium-only roll counts.Mutation TierMultiplierGold ×2 / Diamond ×3 / Ruby ×5 / Emerald ×10 stack multiplicatively on top of the x2 Money gamepass and Friends bonus. Emerald is the apex mutation.