Rick Riordan said this quote

“ Yes, an actual full-sized camel. If you find that confusing, just think how the criosphinx must have felt.Where did the camel come from, you ask? I may have mentioned Walt’s collection of amulets. Two of them summoned disgusting camels. I’dmet them before, so I was less than excited when a ton of dromedary flesh flew across my line of sight, plowed into the sphinx, and collapsed on topof it. The sphinx growled in outrage as it tried to free itself. The camel grunted and farted.“Hindenburg,” I said. Only one camel could possibly fart that badly. “Walt, why in the world—?”“Sorry!” he yelled. “Wrong amulet!”The technique worked, at any rate. The camel wasn’t much of a fighter, but it was quite heavy and clumsy. The criosphinx snarled and clawedat the floor, trying unsuccessfully to push the camel off; but Hindenburg just splayed his legs, made alarmed honking sounds, and let loose gas.I moved to Walt’s side and tried to get my bearings. ”