big guy vs shaw

Not sure as he looks bigger than Holloway and is wearing the Engineer suit.... This big guy does pose a conundrum, maybe its just the angle and lighting, but in other images we see him run through the ship and also have Shaw by the throat in Vickers Room and he shows no signs of being burnt at all. Does he get burnt a bit after those scenes or is it someone else in a suit?

Here is a thought. We have seen Shaw looking through a door window and seeing the large tentacle slip past. We then have seen Shaw walking around the ship in the same suit with an axe, now we have seen the big blue guy appear to be fighting with Shaw. I dont think they are fighting, i think the blue guy is hunting down the tentacle alien in the ship and Shaw is in the way. I also think the big blue guy it Holloway. Why Else would the Big blue guy be in the ship? and does Shaw really think she could take him on with an ax? You also see the blue guy start to go through doors in the ship, Like I said i think it wants the tentacle alien, is that cuddles grown up?