The features form when magma cools beneath earths surface are Volcanic necks and Dome mountains
Volcanic Mountains are formed when molten rock (magma) deep within the earth, erupts, and after cooling it piles upon the surface. Similarly A volcanic plug, also called a volcanic neck or lava neck, is a volcanic object created when magma hardens within a vent on an active volcano. So these two are the features that are formed when magma cools beneath earths surface