Purple Fetin

Purple Fetin is one of three special Fetin disorders obtained exclusively through the Volcano event in The Jurassic. When you sacrifice a cat at the volcano and get a rare critical success, the cat survives and receives a random Fetin. Purple Fetin's upside grants 3 additional rerolls on level-up ability and upgrade selections, giving you significantly more control over your cat's build trajectory. The downside, shared by all Fetins, is a 10% chance each turn for the cat to be AI-controlled instead of player-controlled.

The AI control chance scales heavily with Luck. At the neutral baseline of 5 Luck, the chance is exactly 10%. Stacking Luck to 15 drops it to just 1%, making the downside nearly negligible. At -7 Luck the chance rises to about 20%, and at deeply negative values it can exceed 60%. When the AI takes over, it prioritizes nearby enemies with basic attacks, disregards on-contact effects like Thorns and Poisonous, ignores Counter Attack and Backflip on targets, and may attack downed allies or familiars if they block the path to an enemy. Keeping Luck reasonably high is essential for any Fetin build.

Purple Fetin's value is frontloaded: the extra rerolls matter most in the early-to-mid game when your cat's build is being defined and hitting specific ability combinations is critical. Each level-up with 3 extra rerolls dramatically increases your odds of finding the exact ability or upgrade you need for your strategy. In the late game, once a cat already has its core abilities locked in, the rerolls become less impactful. This makes Purple Fetin ideal for cats where a specific synergy or ability combo is make-or-break for the build. Of the three Fetins, Purple is the most universally useful since every cat levels up, but it offers the least ongoing combat benefit compared to Orange Fetin's kill sustain or Black Fetin's mana restoration. Fetin disorders are classified as Special Disorders, excluded from all normal disorder pools, so the only way to obtain one is through the Volcano sacrifice.