I think the guy walking around naked just did that on his own. I don't think that was for "credit."
However, the other class was one of those student-led classes that were allowed to give a limited numberof credits for bizarre activities. I can assure you that we had none of that when I attended there. The classes were hard and comprehensive and most people were grateful to recive a "C" for their efforts at undergrad level. A "B" was remarkable, and an "A" was almost unheard of.
Graduate school was another story. Grading was "easier" because they thought that if you actually made it to grad school, you were probably pretty smart.
The closest I ever got to an "easy" class was a basic Architecture Review class (1 unit) that I used to fill out my program. It still was pretty difficult, although I did get my "A" -- it just didn't count for very much.