I did service work in the Chevron plant in Pascagoula, MS. One the cold weather hazards was alligators that would crawl up in the units to stay warm.
My only gator encounter at a refinery was at the bayou that ran alongside it. I had to go to some remote infrastructure stuff that was across the bayou from the refinery. Three of us loaded into a jonboat, crossed and did our work.
Returning to the boat a “log” was length wise against the boat. We realized when we got close that it was a gator pretty near the length of the boat. We started chunking wood at the gator until it swam off then got into the boat.
A friend of mine was doing some work at remote gas pipeline pump stations across the western US. He was hiking a mountain trail in Wyoming and heard a rumble of noise that kept getting louder. He got off the trail and back into the trees. A herd of elk came trotting down the trail.