What attacks vegas?

My guess is the 8 eight legged MUTO (Or six legged I don't remeber). In the newest trailer there's a monitor where you see it attacking what looks like Vegas, so that's my guess. Welcome to the forums!

8 legged MUTO I'm pretty sure!

Welcome JMtrude and I hope you have a good time here.

As for my thoughts, I will have to speculate that it is one of the MUTOs, as others have. Though, I will not speculate on which one.

It's probably the muto that lacks wings as most of the damage is done on the ground!

Probably the 8-legged MUTO coming to her partner the Hokmuto.

My guess it's the winged muto since it has the ability to fly and getting to Vegas would not be a problem. In the extended trailer there is a scene of troops opening a door that leads to the outside. You get a quick glimpse of detroyed city and ruins in daylight. The scenery looks like the Vegas landscape. Maybe the winged Muto, presumably the female senses the prescence of her mate in area 51 in Nevada and breaks him out. They have already said that she is much bigger and stronger then the male. My guess is they wreak havoc in Vegas then leave to head towards Hawaii. She becomes impregnated by her mate then goes somewhere to lay her egg leaving the male alone. Then there is a confrontation between the male and Godzilla at the Hawaii airport. The male gets his ass handed to him. Then later in San Francisco we have the finale between mom,baby muto and Godzilla. Sounds good to me.

@REGGIE138 - That sounds like a pretty accurate synopsis from what I have seen. Thanks for spoiling the entire movie. haha.  

@JMTRUDE Thanks just having some fun with it!