No, they're the exact same other than name and likely item ID. You can learn, and pay for, both. This is also true for the Lil' XT and the Landro's version, and the Tsunami relief hippogryph was the same as the old one until they tweaked its beak a little.
I'm not sure why they have two versions. Maybe it's sort of an incentive for TCG players, a chance to get the Pet Store pets for "free." But since they're not the exact same item that's not really true.
yeah i was wondering this myself. are they the same. cuz i just got landros lichling, which is said to be the mini version of kelthuzad on the redeeming site. but i remember there is also a pet called simply lil kt from the blizz store.