http://www.sonic-online.com/sonicpassion/
There was actually a forum for people who were. I'm dead serious. And not only for Oddworld characters, so it seems.
The forum seems to be down now, this site is the only proof of its existence. Thoughts? I find it hard to say anything about it, I'm still surprised.
Kudos for Vexen for finding this. I'm never going to ask.
**NOTE**: I posted this in Off-Topic Discussion for a reason, mainly because it's more about people than Oddworld in itself. Also, I doubt you'd want this kind of thread in Oddworld Discussions :P