1. Similar to a bandwagon, a goofwagon is a person who's goofiness is so powerful that it infects anyone surrounding them. They will slowly amass followers of their goofiness until the person leaves or the drugs wear off. One should be careful when following a Goofwagon. They tend to have only silly intentions in mind.
2. A strange looking wagon.
"Hey, who is that girl over their doing cartwheels in that flaming tutu?"