Here is the hard truth: If you see a website offering a "direct download" or "torrent" for this specific version, you are walking into a minefield of malware, fake links, and legal risk.
Sometimes users confuse "Crocodile Physics 17" with the much older "Crocodile Physics 605." Version 605 is often considered "abandonware" (though legally still gray). You can find older versions on archive.org. and is actively sold, so you will not find it legally for free.
While individual home use may be free, classroom or commercial use typically requires a paid license. Modern Alternatives