It's usually called Zalgo text, and it's what you get when you start stacking all kinds of Unicode diacritics on poor unsuspecting characters.

https://en.wikipedia.org/wiki/Zalgo_text

This is the best generator I found: https://lingojam.com/GlitchTextGenerator

I find http://animalswithinanimals.com/generator/generator.html much more controllable.

Interestingly I get different behaviour per browser/OS. Firefox/Linux clips it to the bounding box of the parent element, Firefox/Mac and Safari/Mac clip it to the line height, and only Chrome/Mac lets it extended further.

Firefox and Safari on iOS 15 both render all the glyphs attached to the base character. Vivaldi, Chrome and Firefox on Win10 all render them stacked and overlapping the parent and child comments.

Huh, I tried it in Chrome to see how it reacted here and it maintained about the same position as it did in my usual browser, Firefox.