I actually bowl for sport, so I'll give my insight.
Those are polyester bowling balls which are basically used to throw straight at a single pin spare. They don't hook as much as the other types of bowling balls such as reactive resin and proactive particle resin. In fact, they tend not to hook at all so they're pretty useless if you're throwing your strike ball.
I've seen some people throw them, there's also a Chyna one, and from WCW there are nWo and Goldberg.
Since polyester balls don't have to be made especially to perform, they're getting some interesting new designs. If you've ever seen the movie Kingpin you see Bill Murray throwing the clear ball with a rose in it, that's available as well as one with a bowling pin, a skull and a Budweiser bottle.