Are there two pegs that come up higher than everything else? Or is that closest mound of plastic a result of the nozzle driving into the part? If there are supposed to be two pegs of plastic, it looks like that close one is getting too hot. You can add a cylinder that goes up a little higher than the extruder part just to burn some time between layers. That will let that peg cool down and come out better. Maybe a cylinder that is 1" in diameter would do the trick.