[rich_sasha]

I read once a suggestion to serve gzipped requests which, gzipped, are tiny, but un-gzipped are enormous. Like GBs of 0s.

Not sure how you actually do it and if it serves your purpose but sounded neat.

[e1g]

It's called a "zip bomb" (popularized by Silicon Valley [1]), and there is a good guide (and pre-generated 42kB .zip file to blow up most web clients) at https://www.bamsoftware.com/hacks/zipbomb/

[1] https://www.youtube.com/watch?v=jnDk8BcqoR0