Man, Jim Henson was only gone a few years and they were already starting to perform horrible Moreau style experiments crossbreeding the alien girl from Explorers with SPEWEY.
It was due to things like the Muppets that Jaleel White felt TGIF lost its way:
http://articles.orlandosentinel.com/1997-07-18/lifestyle/97071 70555_1_family-matters-cbs-urkel
Luckily, White stayed on the Miller-Boyett train with Patrick Duffy and an alien nanny played by Balki.