I am planning on turning the space where an old laundry closet used to be into a shower area as part of a more extensive renovation (house was built in 2006). As part of the planning and design part of this process I came upon this black thing sticking out of the wall, which I have no idea what it is? My best guess is it is an old sealed off vent pipe? I figured I would ask here (pic included) to see what it might be before I start tearing up the place. Additionally, if there are any tips on how it could be removed or hidden behind the wall (if possible/permitted by code) that would be appreciated.
For context, the water tray for the old washer is on the bottom. Cold and hot water connections (not seen in pic) are further up on the wall to the right of the unknown device.