What does it mean when something charges at me from the tall grass

pokemon-sun-moon

As I entered Route 2, the screen narrowed and I noticed something rustling in the grass. When I walked towards it, whatever it was rushed at me and initiated an encounter.

In this case it was a Makuhita, which I hadn't seen before. Does something rustling in the grass then rushing towards me mean that it's a rare or particularly strong Pokémon? Is this a scripted sequence?

Best Answer

The first one on Route 2 is scripted because the guy next to the tall grass tells you all about the rustling Pokemon.

He basically tells you that these Pokemon have a higher chance of carrying an item. You can move said item from the Pokemon to your bag before you put them in a PC box.