Scooby-Doo was one of my favorite cartoons growing up. Although it never explicitly mentions philosophy, it does, through example, teach kids about philosophy's most fundamental branch: epistemology, the branch that asks "How do you know what you know?"
In Scooby-Doo, Scooby and the gang are often faced with a mystery involving a supposed ghost or monster. Of course, they know that ghosts and monsters don't exist. Or do they? It's up to them to solve the mystery and find out what is really going on. What inevitably happens is that the ghost (or monster) is revealed to be an ordinary person wearing a costume. Sometimes, at the end of the show, there is something that happens to make you wonder if there really was a ghost (or monster).
Scooby-Doo taught me to be skeptical of peoples claims. It provided the momentum I needed to become interested in science and philosophy. If you have kids, I highly encourage you to share this with them. We need a world where people know how to think for themselves. Oh, and I hope you like my attempt to draw Scooby and Shaggy!