Hello, I created this account a while ago to post about this then forgot about it while waiting for verification.
Anyway, when Kids Next Door used to air on April Fools Day, they aired edited versions of the episodes with humorous sound effects added. While the original version of each episode is relatively easy to find, I've been unable to find any of these edited versions, and very little evidence that they existed.
I also don't remember which episodes did air as April Fools Day edits. Maybe we could find some sort of TV guide thing from when they aired? Knowing which episodes aired in this form would definitely make these easier to find.
Also I know for sure Cartoon Network continued to do this while airing reruns in the early 2010s.
Hopefully someone else at the very least remembers these as well and can confirm they did actually exist.
What I'm getting from that thread is that the gag originated in 2010 and is something Cartoon Network did and doesn't actually have anything to do with KND.
2010 is the only year I remember for certain that this happened now that I think about it, I thought they did this during the show's original run too, but I guess not. After all, we're dealing with something that happened about 10 years ago.