Way before YouTube and also before Flash, in the late 90s and early 2000s, is when weird and silly animation and video began to pop. Hamsterdance.com, dancing baby, Kompressor[1], and so many others (abevigoda.com) predate the 'weird YouTube' phenomenon with nothing more than basic HTML and a few JPEGs. And because of that simplicity, you can still enjoy them as they were thanks to archive.org.

[1] https://web.archive.org/web/20020407141113/http://www.kompre...