It's a huge freshwater fish, easy to catch and eat, and tempting to introduce into non-native waters.
And when it shows up? It will eat everything it can and probably drive competitive smaller fish extinct. Good intentions are rewarded with plenty of Nile perch (for now) but a degraded ecosystem in the long run.
There are bright shiny objects you can bring into your life (that project, that employee, that new office) that might just push the other useful items aside. You get hooked on them or they demand more attention or they make too much noise and the less-shiny projects or people whither away.
An art museum brings in a traveling show from a famous artist. It's important, expensive, time-consuming and brings big crowds. For the next six months, all eyes are on the big show. And then, of course, a vacuum, because the important but less glamorous work didn't get done.
A lawsuit or a merger or a shift to a new office space might seem like a good idea at the time–but be careful what you wish for.
The Nile perch is nefarious yet applauded (in the short run). Don't be afraid to call it when you see it.