Wheres the decimator tool?

Based on a pic that some website was showing, the descimator tool is supposed to be in the Mesh panel right beside autosmooth. But its not. Does anyone know where else it might be?

it’s now in the modifier stack with array, subsurf, etc

Thanks man, I appreciate it. But now I ran into a problem. Is there any way to reverse the decimation to make more poly’s instead of less?

Thanks again.

use the script version then