In most 4chan boards (mostly /v/) when someone said 'thick' to a female image, they'll respond with "Did someone say thick?" and "Thicker!" and turn it into a thick female thread. Similar to 60's Spider-Man when someone suddenly turns it into a 60's Spider-Man thread. I did remember seeing a MSPaint comic about a thick thread but I didn't save it.
Did someone say 'thick'?? Oh wait, I did.