Fighting the Terrox is hard enough without a ghost Terrox sticking around to get in the way afterwards.
I killed one of the Terrox, leaving just three but it stuck around as a visual bug on top of/behind the others. The living Terrox could move into that "spot" and could be fired upon without hurting the ghost Terrox. Eventually combat ended with the ghost still haunting me but since it didn't cause the combat to stall/break the game I guess its not that big of a deal. This is the only time I've ever seen this. For reference/if it matters. This was the first of a Salvage card produced back-to-back fight.