If you take a couple of seconds to search "ass in nine"
you’ll find that several fine artists
(let’s take "fine" with a grain of salt)
have illustrated donkeys with or near the number nine.

Sometimes it’s sculpture, sometimes it’s painting.
Always it’s punny.
It never takes much to find these works of art
(let’s take "work" with a grain of salt).
Just some basic web-searching.

The results are
the correctly-spelled version
of the initial search.