It's done by some Millenial or GenZer animator. It's a series of videos made on Source Filmmaker that feature prominently the head of Half-Life character, Gman, amongst others, protruding out of a toilet, doing a comically animated dance to various remixes of popular songs with the special featuring of the line “Skibidi”. The remixes are all original for the videos. The extremely short videos were initially of only the toilet man dancing with fellow toilet folk, but it has evolved to follow the conflict between skibidi toilets against camera head men struggling to take over the world with increasingly ridiculous scenarios of combat and warfare that include mechas, gore and sci-fi weapons. It has no dialogue, the plot is implied via animation exclusively.
The thing went popular on the YouTube shorts algorithmic suggestions and since it has no dialogue, it features repetitive and catchy music and a bizarre and amusing subject matter with immature bodily function humor, it garnered massive attention by small children. I say that Gen alpha barely passes 10 years old right now, so we should give them a break before imposing inflexible marketing labels upon them.