New specimen idea

[Benedict]

"Earthmover/worm/digger" (listed up some names for the speciman)
-travels underground/building walls and pops up to attack the players. The visibility of this specimen would be similar to stalkers, and it would be visible to commando's range. While this specific specimen is moving it the ground would look kind of bloated and have a dark spot on the ground to make it noticeable for the players to attack on sight.