"Trey Parker, one of the creators of South Park, was raised in Colorado, where his father attempted to teach him Buddhism. Years later, Parker and his animation pal Matt Stone have brought to life the teachings of Alan Watts, the comparative religion expert and philosopher. Under the FurryCarlos Productions banner, the two tapped South Park animators Chris Brion and Todd Benson to keyframe some of Watts’ recordings."
There are six of these and I'll post them all here. The last one ("Alan Watts - Zen.swf") is probably not made by Trey & Matt since the animation style is completely different but I'll upload it for completeness sake.
It says in the flash "A FurryCarlos Production" but I can't find info on any such studio ever existing so they probably just put it there for fun. The copyright notice at the bottom of the page I linked to above mentions the years 2001-2004 so it's pretty safe to assume that these flashes were created around 2002. South Park season 6 aired in 2002.