I don't think it's Skullcruncher is Crescent so much as the one in the combiner pack is Skullcruncher while the Battle Master is Crescent. Edit: I lie, apparently he is. So it seems Crescent was the codename and Skull was just short for Skullcruncher. I haven't seen Crescent being mentioned as listed for Studio Series before, just the listing for the Battle Master, code name 'Skull', and once with the assortment as 'New Transformation' (New Transformation 6 was a code name for Beast Battle Masters). Unless you're thinking of the core figures code named Hydra and Delta 2 (Freezer is Delta 1).