Sorry if it being a cartoon series is a problem but it is a horror themed show.
I tried Yahoo Answers but to no avail.
It was on a while ago ( maybe 5 years or so) and ran on itv( citv), in the uk. It starred a "normal" family who for some reason moved to a monster inhabited world. The monsters weren't evil but they were weird. The parents and son acted as though it was a normal town whereas the daughter didn't like the place. The also had a pet cerberus with one cool head, a dopey head and an imbetween head.
Do you think it might be worth emailing itv themselves, they'd keep old schedules wouldn't they?