It is pretty simple, all you have to do is place a bunch of trapdoors, and have a skeleton follow you. When it gets on the trapdoors, it starts moving super fast. I have a video so you can see what happens.
Edit: Seems like it happens on other not full blocks, but the effect seems more prominent on trapdoors.
I haven't checked other versions, but I guess it doesn't matter that much.
There's a webm and a gfycat link if the video doesn't work for some reason.
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I tested this in 1.15.1 on Linux.
The bug doesn't affect pillagers or zombies.
The affected blocks are: honey blocks, slabs, soul sand, trap doors.
The unaffected blocks that I tested are: slime blocks, stairs, fences, carpet, fences with carpet.
Video