Drivel, I’m sure it’s not Rebus. I googled it, and can’t find any info on Rebus cartoon/animated TV series at all.
Ruby, you are along the right lines. There were some credits that read like they were east european names.
C’mon you guys. This is doing my nut in.
It was a 5 minute cartoon, about a tiny little creature that lived in a crack in a wall inside a house. I think it was blue-coloured. They showed around midnight, back in the late 70s or 80s.