Of the OO languages I've used, Perl is most like C++, in that it gives you more freedom than most. Both also give you more rope to hang yourself with, but that can (IMO) help you learn a lot too.
Two of my favorite Perl features are ties and closures. If you learn these, you'll be too spoiled to learn Java.
Even though you need certain features to do OO "right", it's my opinion that OO is mostly a way of thinking. I've seen C code that's more OO in its design than some poor Java code I've also seen. The thing that forces most people into OO ways of thinking is tackling large problems with identifiable patterns. Most developers innately want to fit the patterns they see emerging from any problem space into neat packages of some sort. If you start thinking that way, OO will follow.
If you do choose to learn Perl OO be prepared for a lot of people wanting to constantly argue that Perl is not an OO language. Usually, by quietly solving the same problems in less time they go away.