Mark Rosewater, in his 3rd podcast about the Innistrad Set. said that this trope has it's origins in video games. He said that zombies are an ideal video game mook  because they come in mass, are slow, typically stupid, and typically aren't able to withstand ridiculous amounts of damage and thus are low threats on their own. He said Fast Zombies were a progression on that enemy. Such as an Elite Mook, or a Video Game Boss.
- His podcast is named Drive to Work
- Not that innistrad has fast zombies (aside from maybe Abattoir Ghoul, which has first strike, and seems to be able to prepare you a meal as a triggered ability). He is a fan of large masses of Plodding Zombies, and as head designer of Magic R&D, he has quite a say in how things go.
- Feel free to look at the Night of the Living Mooks page.
- In some case they only go down easily if you headshot them