I work at an airport for a major air carrier. One day a few years ago, I walk through the hangar and there is a 757 parked inside with the doors closed. and there are like 5 General Managers and a couple of directors in suits staring at the plane. There's a huddle of mechanics to the side and I ask them what the hell's going on.
One of them replies, deadpan,"Cheetah's loose on the plane."
Mechanic: "You know; Lion, Tiger... Cheetah."
Apparently, we were transporting two cheetahs from a zoo in Oregon to St. Louis, when one of them got free in the cargo hold. The baggage handler goes to open the door and almost loses an arm before he can shut it again. SO, there we sit, trying to think of how to get the door open without letting an angry cheetah loose in a confined room.
Oh, yeah, on top of all this, there is a HEART on board for transplant, we have to get to it before the thing gets hungry and curious.
Eventually, we call the zoo, and they crack the door and tranquilize the poor thing, and cart him off, the heart gets on its way and we all live to tell about it.
We have tiny cameras called borescopes to inspect the plane. They snaked a camera inside and were looking at a little video screen to monitor the unruly passenger's activity so they could aim at the cheetah.
Someone had the bright idea to bring a 7 foot fence over in case the thing got loose, but I'm pretty sure a 7 foot fence is little more than a speed bump to a cheetah.