Se back in 1.15 I was messing around with falling blocks and discovered that making long chains of them looked cool, a little like a snake.

So I made them into snakes.
I promptly forgot about it for a while until I remembered it earlier today.
I updated it for 1.18 and boom
no resource pack needed so easily added undetectably to servers

For the 5 people that care about the technical side, here is how it works:
It's mainly a silverfish
Falling blocks are being summoned onto it constantly
The blocks are killed after like 300 ticks or so
Because you can't hit mobs through falling blocks, there is an invisible NoAI size 2 slime on it
When the slime is killed, it kills off the silverfish
Actually pretty simple