Specifically, "The Flying Spaghetti Monster", which was originally created by a then-24-year-old physics graduate Bobby Henderson in a letter to the Kansas State Board Of Education prior to the Kansas Evolution Hearings as an argument against teaching intelligent design in biology classes.
It is a clear parody religion, although followers claim it to be "genuine" when it suits, (e.g. the recent news story of Christopher Schaeffer, an American politician that was sworn into office as a New York council member while wearing a colander on his head).
The movement is less than 10 years old, and in case you're not familiar with it, it is basically a modernisation of the Russell's Teapot argument against religion - that the onus of proof is on the person making the outlandish claim - combined with a new take on the old scientific rule that "correlation does not necessarily mean causation", shown using a graph that plots global temperature throughout history against the total number of pirates in existence at the time. "Fewer pirates = higher global temperature!"
As long as we didn't use actual artwork from the site, or quote the "religious texts", The Gospel Of The Flying Spaghetti Monster and Loose Canon, would we be able to create t-shirt designs about the religion on the basis of "badge of support, loyalty or affiliation", i.e. Arsenal vs Reed?
I've just realised by taking a look at the wiki page to refresh my memory of Arsenal v Reed that this might actually be more of a trademark question rather than specifically copyright again. Sorry.

