The Ball Python was created by (myself) JVM and Rex in 2007 and was the first-ever snake for the games. It likes the Savannah environment but is easily pleased. I coded it myself, and Rex skinned and meshed it. It was originally a teaser for a reptile-focused expansion that was cancelled.
It requires Zoo Tycoon 2 and the Zoo Tycoon 2: Endangered Species and/or Zoo Tycoon 2: African Adventure expansions to use ingame.