That is your factory skid plate. It is often referred to as a shovel because it has a tendency to collect rocks and mud. It also appears as if you've got a transfer case drop on your Jeep which helps with the lift angles. To get rid of it you can buy an aftermarket skid plate and bolt it up....but then you'd lose your tcase drop which might cause you to need a SYE (do a search) and a new rear driveshaft. Its all one big spending circle. Welcome to the club.