This challenge is very unique. It involves adding a completely new edition for jokers. The "mutant" edition doesn't appear naturally and is exclusive to challenges.
The Extinction challenge starts you with an Eternal Mutant Perkeo that, instead of creating negative consumables, creates negative jokers.
You are also given a cavendish and an eternal oops all 6s.
You only have 3 joker slots, so you can't buy any more jokers. Also, no skipping blinds this time.
At the end of every shop, Mutant Perkeo will either duplicate a cavendish or an oops all 6s.
The more cavendish copies you get, the higher scores you can reach. However, more bananas means a higher chance that at least one of them will perish.
If Mutant Perkeo copies the dice, then the chance that any cavendish perishes doubles.
If you reach 10 dice, all your cavendish jokers will have a 1024 in 1000 chance of perishing. game over.
However, it's entirely possible to get to the end of ante 8.