I finally tossed all the VHS and I may have done a little happy dance when that one went into the garbage bag.
edit to add: just realized you may not know what I'm talking about. There was a short film made many many years ago called (I think) The Human Centipede, which was some psycho scientist who... well, yeah. Dad found it in a collection of horror shorts on VHS and it was bad enough that he called it the most disturbing thing he'd ever seen. I can't find it on IMDB. All they have is stuff that's way too new to be that movie. I never watched it, but Dad's gory description was enough to make me gag.
The Human Centipede came out in 2009, and the sequel, Human Centipede Second Sequence in 2011.
There are no earlier versions. VHS was long gone by then.
The Human Santapede Christmas Special came out in 2014.
So you and your Dad mist have it mixed up with some other movie.