One of the guys in my group wants to make a shapeshifter. Any thoughts on how to mimic this? Would it be better to make it mundane ability-based, or perhaps it would work better as a psuedomagical ability?

Here's my initial thought: Shapeshifting as a "magical" ability (primary or secondary?) with animals as words (e.g, Wolf, Bear...). Then also take secondary abilities that are limited to animal-form (e.g, Claw attack, etc). Or perhaps the Primary attribute "animal attack" or something.

However, this is rather cumbersome. It would feel better if there were a way to make it more natural...but maybe that's something that only occurs at higher levels... hm...

I'd have the player make two characters - one for each form - and take a Shapeshifiting Ability for each one. In order to change - or not change, depending - he'd have to make a Shapeshifting Test (hmm... Wherewithal + Ability? That sounds good.) vs. Medium difficulty.

If you want to balance this some more, make the player split XP between the forms. I'd let him choose how to split the XP, actually.

Oh, I like that idea! I had considered the idea of multiple "characters" for shapeshifting, but it seemed unbalanced. But the way you suggested makes a lot of sense to me, esp. the bit about splitting XP (which I think would be necessary, since he has twice as many abilities, right?). I knew there was a reason I paid you the big bucks. ;-)