Dueling Shows: Along with Family Dog and Fish Police, ...Critters was one of several attempts to cash in on the success of The Simpsons with a wider market of prime-time animated shows. Not only did The Simpsons, of corse, slaughter them all, but would later rub salt in the wounds during their next "Treehouse of Horror" special, where tombstones with the competing shows' names are in a pet cemetery.
Follow the Leader: As mentioned above, the show was failed attempt to cash-in on the success of the then-new prime-time animated sitcom The Simpsons.
Keep Circulating the Tapes: Fox may have let re-runs slip over to Turner/WB (as this show did air in the early days of Cartoon Network, when the channel was a 24/7/365 showcase of Hanna-Barbera animation, both popularnote like The Flintstones, Scooby Doo, Tom and Jerry, and Yogi Bear and obscure), but DVD rights apparently not so much. Even though the one that doesn't have it would probably release it if they did.