It's similar. In HP, the patronus is a charm used by a wizard/witch. In particularly dire situations (i.e. chasing off an evil beastie whose forte is making you really, really depressed), you use the patronus charm by thinking of your happiest memory ever, then pointing your wand and shouting "expecto patronum". Your patronus spooges out of your wand in the form of shimmery light in the shape of an animal which chases off the baddy. The animal is your patronus - you don't get to pick, so I guess it is pretty much your totem animal.

(by the way, in general i would agree with you on the wolf/hawk thing, but in the crossover's canon i'd stick with the unicorn/balrog verdict *g*)