Count Von Count first appeared during season 4 of Sesame Street
A count who loves to count isn’t just clever wordplay. In early folklore when vampires were more ghoul-like, they were often depicted with arithmomania, a disorder where the individual has a need to count their actions or surrounding objects.
Hundreds of years ago, this was used as a way of delaying vampires from attacking, for example throwing handfuls of seeds on the ground was thought to force them to stop and... well, count.