The oldest reference to the coral I could find by GARF was in an article from 1998, at which point they were already propagating and distributing it at scale. I know I talked with Leroy in the late 90's about it and if I remember correctly he was the one who came up with the name "green slimer." I don't remember where he got it from. Lol seemed insignificant at the time, and I was a teenager.
For what it's worth, the reef breeders obit for Leroy said that he popularized green slimer and purple bonsai, but that they were present in the trade before he got them.
This makes sense given that he was in Idaho.
@reefbuilders do you know more of the history here?