Wild Kingdom is a intel document in Resistance: Retribution.
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The Maquis fortress was huge, but the Burrowers made quick work of perforating every critical wall, floor and ceiling. An entourage of Leapers, Hybrids and other gorillas would pour out the Burrowers troop compartment and gut anyone still alive. One Burrower destroyed the pump station water systems, and flooded its own exit tunnel, allowing me to swim down and recover a drill blade that had snapped off the Burrower's face. Military intelligence has been quite accurate analyzing Chimeran creatures and machinery, but it seem we've been wrong about the Burrowers. Until now, we believed they were pilot operated drilling machines. But this drill blade was a large, sharp, steel arm with a mound of torn flesh and bone at the base. We know it takes one human to make a Menial or Hybrid, and several more to make larger creatures, but how many sodding men does it take to form one of these beasts? Ten? Twenty? A better question is, was this even a person to begin with? Ask me, they started with a shark or a polar bear.
-- Journal Entry, 03 September, 1951 -- James Grayson