I strongly suspect they aren't then, but it is faintly possible I suppose. I have never actually seen giant pixie tads for sale(and I usually have a decent handle on what is available) so I am making an educated guess that that particular shop doesn't know what it is taking about in this case. If it was S&S or Pets A Plenty making such a claim I would say the odds would be much better. Right now I would say the odds are probably somewhere between very slim and none that they are actually giant pixie tads.