You see, he didn't try particularly hard to conceal the crocodile -- he just stuffed it into an oversized gym bag and hoped for the best. And he almost made it, too. But as the plane approached its destination, the crocodile finally decided that enough was enough, and also finally realized that a goddamn gym bag is no match for razor-sharp crocodile teeth. So that's when it burst out of the gym bag and started thrashing around the cabin like ... well, like a crocodile.
The flight attendant panicked and made a beeline for the cockpit. Which wouldn't have been so bad, had all the passengers not followed suit and stampeded right after her (hopefully leaving "there's a crocodile in my duffel" guy at the "there's a pissed-off crocodile right behind you" end of the line). The sudden shift in weight threw the small plane off balance and it promptly crashed into a house just a few hundred feet from its destination.
"Ladies and reptiles, this is not a drill. Please take your seats, our fireball will be commencing shortly."
But our crocodile-c*m-movie-villain wasn't done just yet -- believe it or not, it actually emerged from the crash unscathed. But this real-life Syfy Original Movie plot quickly came to an anticlimactic end when the crocodile was hunted down and dispatched by a witness who happened to have a machete handy (read: anyone who lives in the Congo). Because apparently machetes can even take out plane-crash-resistant super-crocodiles, which explains why they're the number one item on everybody's zombie apocalypse Christmas list.