Why do some people call programs "codes"? I hear this a lot from mathematicians and physicists.

Because the act of writing a program is known as "coding".

I always thought it was "programming".

I was once a physicist and I never understood it either. Maybe because a lot of software they produce is a blob of code?

I'm not convinced that 'creepy' is the right word but this is a fascinating collection of art; the puzzling, the underhanded, the clever, and the impressive.

I hope the collection will grow over time!

The right term is obfuscation. And if you'd done your research well, you would have found tens of them on the perl monks forum....... way more intriguing and "creepier" than your examples

And since 1984, well before Perl was a thing, C coders have had their "International Obfuscated C Code Contest".