Blobber 2.1 for Mac is available as a free download on our software library. The program lies within Theming Tools, more precisely Multiple Desktops.
From the developer:
Blobber allows you to replace the wait cursor in MacOS 10.2 Jaguar. Blobber is the result of a great chat in the MacNN forums. People have been trying to replace the cursor in Jaguar ever since the Aqua Blob was replaced by the Rainbow Pinwheel. It has been discovered how to replace the cursor, but it requires the terminal which is a part of MacOS X with which few are comfortable.
You may want to check out more software for Mac, such as Cisdem WindowManager for Mac or Scrapbook with Neko, which might be related to Blobber.