Hey naoutlaws999 !!!
I found it!!!
We searched Google using the words "willard snake" and sure enough, found some one talking about the "Willard like movie only with snakes"... LOL
It was made in 1972, right smack between "Willard" and "Sssssss"... and it's called "Stanley"... between the snake theme and the S it's no wonder I have had them mixed up all these years.
By the way, if you like these types of flicks, if you like Willard etc, you should check it out... it's pretty cool for the time it was made and all.
http://www.imdb.com/title/tt0069308/
Also someone has a web page about it with stills from the movie, inlcuding the pool scene that stuck out in my mind even 35 years later. LOL
http://videoaddicts.8m.com/stanley.html