I'll call this the 'Cannibal Corn', though since it's dead and frozen, naming it is hardly a concern.  I found this baby amelanistic corn this way in its individual shoebox cage, so it was not due to a struggle with a cagemate.  I hadn't fed it recently either, so the centrally located lump was not a mouse.  Maybe that's where its own rear end was curled (doubled over), because its tail was obviously folded over.  

Why did it do it?  Definitely an enigma!