Fine. It's yours.

You paid money for a grumpy cat. It has noticed, and it's not impressed.

1. Drag FatCat into Applications from the disk image.
2. macOS will say it "can't check it for malicious software". That's because FatCat isn't notarised by Apple yet, not because it's harmful.
3. Right-click FatCat in Applications, choose Open, then Open again. Only the first time.
4. On macOS 15 or later: after the warning, open System Settings, Privacy & Security, scroll down and click Open Anyway.

Or skip all of that: paste the Terminal line above. macOS 13 or later. Keep this page: the link is your receipt.

Hm.

I can't find a payment for this link. If you paid, give it a minute and reload.

Checking your payment. The cat is counting it.