as for what the oldest one is, i'm not sure. but this image was posted to a bbs in 1989.
does that count? well it's not really the internet. also, not really weird enough.
no im wrong its actually way too weird.
the "weird garfield" internet phenomenon dates to at least as early as 2006, to this thread on the Truth and Beauty Bombs forum.
this thread spawned the silent garfield meme (comics improved by removing garfield's speech bubbles), the garfield minus garfield meme (later exploited by Dan Walsh in 2008), and "garfield has crazy eyes"
even before this, there was the garfield shuffler in 2004. it goes way back
back to Barfield.
i never see Barfield mentioned in lists of weird garfield stuff. it's like everyone forgot about it. i always fear stuff like this will disappear from the internet. thank goodness for wget.
show Elbe Spurling some love. she also did the brick bible. (bible depicted with legos) https://elbespurling.com/