Have you tried leaving him in, say, a deli cup with the thawed pink overnight? Sometimes given a longer time in close quarters with the food, they'll decide it doesn't look all that bad after all. At least, my adults tend to eat frozen more readily given a few hours in a box in a dark corner. Good luck,

-P
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1.0.0 Normal corn snake (Frito)
1.0.0 Creamsicle corn (Tang)
0.1.0 Ghost corn (Raynham)
1.1.2 Bay of LA rosy boas (Rivet, Cali, and Cali's unnamed babies)
0.1.0 Cape Gopher (Mole)