Mr. Okamoto and Mr. Chiba identify the blind Frenchman, who sails up to Pi late in the telling of the first story, as the hyena. This guy complicates the allegory, but, like we said, it's not exactly your standard allegory (see "Symbols, Imagery, Allegory"). How can the hyena be both the cook and the Frenchman? Well, Mr. Okamoto and Mr. Chiba think that since Pi kills the cook and Richard Parker kills the hyena and the blind Frenchman, Pi has mapped the both the hyena and blind Frenchman onto the cook. Also, the Frenchman – though at this point Pi thinks Richard Parker is speaking – admits to having killed two people, just like the cook did.
Should we trust those pesky investigators? We're not sure. Pi, in a delirium of starvation and guilt, could imagine the blind Frenchman. In the second story, it'd be like the ghost of the cook returning to haunt Pi. If it were a horror movie, the hand would rise from the water!
We have no answers for how this works in the allegory. You should send Yann Martel an email. The blind Frenchman does highlight Pi's madness. And the depravity of cannibalism, which, if we must remind you, your dear Pi sort of accidentally commits. In both stories. Perhaps it's a good thing Richard Parker gets rid of this guy quickly: he complicates the allegory and perhaps represents the evil that Richard Parker, through his own violence, dispatches.