I had those and let them go a couple of years ago. I regret that soooo bad. I wouldn't really consider them knock offs, but kinda. Alot of time they are better than the originals.
So after much scavenging through the hells of wal-mart and B,B&Beyond, I finally managed to find the last one I needed yesterday. This is all 12 of the new Madballs Series 1 & 2 released so far. Here's hoping they actually release Series 3.
I used to love these things! I think I still have my old Screemin' Meemee, the horned cyclops (Hornhead?) and the big football one that is shaped like a deranged bomb somewhere. So awesome! I agree. These are just begging for the vinyl treatment.