I FOUND IT!!!!!
In the episode, the Taco was an alien that took on a pleasing form for the kids on South Park so that they wouldn't be scared. (The Taco also pooped iced cream - a request of the kids.)
After I saw this episode, I saw a hockey game in Florida. A vital note here: I was drunk at the hockey game and wasn't sure if what I was seeing was real or not.....