When I'm talking about taming challenges today I'm talking about pets that have a mechanical challenge or trick to the taming process, or pets that are rare spawns with unique models. There are of course scores of rare spawn pets that look identical to common pets, and even a lot of rare spawns that have a slightly different coloration but otherwise are identical to common pets (and you can see a list of these at Petopia).
While it might be hard to wait for a King Krush spawn, for example, it's not something that fills vast numbers of hunters with the need to get that pet. Spirit beasts on the other hand ... spirit beasts are like a plague of uncontrollable desire that spreads burning through the pet collecting loins of the hunter population, so I have to include them.
If you aren't the kind of hunter that is really into pet collecting, today's column is not for you. If, however, you are the other kind, then here is a list of all of the hunter pet taming challenges currently in the game.