The "ZOT" came along after the creation of Admin Mods on 9/3/01 but before 11/27/02.
The thread I found with the Nov 02 date had a lot of explaining of "ZOT",
so one can assume it was still fairly new.
The Admin Mod profile page says they invented it, but gives no time frame.
The first mention of "Viking Kittens" I could find was from 4/3/03. In that thread it appears they'd been around for a short time.
I found a long "Zot" thread on 2/4/03 which did not have VK involvement.
I conclude VK's started between Feb 03 and April 03.
Not being a Cat person, I've not gotten into the VK's. I prefer a good old fashioned ZOT.
Before we were infested with trolls, we had a bad case of disrputors.
During your searches, did you find out when the first MODS appeared? I know that FR didn't have any until at least 2000.