After reading about "The Banana Splits In Hocus Pocus Park" for years, today I finally got to see it, on the Boomerang channel.
The one thing that I noticed most was that the voices of several of the characters kept changing during the show.
The ones that I noticed changing were Drooper, Hocus, and Pocus.
Allan Melvin normally supplied the voice of Drooper, but there are quite a few lines in this program that are definitely not him, but someone doing an impression of him.
The same is true for Howard Morris, who provided the voice of Hocus. There are quite a few scenes in which someone else (I think it sounds like Don Messick) is doing an impression of Howard Morris' character called Hocus.
IMDb.com says that Howard Morris also provided the voice of Pocus, but I can't tell it it's him or not. But in any case, there are two different guys providing the voice of this one character during the program also.
I wonder if there was a problem with the voice recording, and some of the lines had to be re-done, but the original talent couldn't be found in time? I don't know.
Speaking as a fan of these voice artists, I find it fascinating that these characters were voiced by more than "just one guy" during the one-hour program.