From the official Resident Evil 5 website:

"The biohazard threat has not ended: Just when it seemed that the menace of Resident Evil had been destroyed, along comes a new terror to send shivers down player's spines. Chris Redfield, returning Resident Evil hero, has followed the path of evil literally around the world. After joining a new organization, Chris heads to Africa where the latest bioterrorism threat is literally transforming the people and animals of the city into mindless, maddened kittens. Chris must take on the challenge of discovering the truth behind this evil plot. In Resident Evil 5, Capcom teaches the player to fear the kittens as much as they feared zombies in previous games."

This kitty is merely feigning death - be sure to torch it lest you face the wrath of a crimson head kitty. In Resident Evil 5, the T-virus mutates normal kitties into Jimmy "Superfly" Snuka kitties. ....clearly the mastermind behind Resident Evil 5's mutant kitty plot.