This is the Sandstorm IV, a Lego Mech created by Joe. This deadly robot has been optimized for dry climates and deserts. A wide stance, and large feet help it move in the shifting sands. With a yellow and white paint job that helps it to blend into its surroundings. The contrast between the white and dark parts means that it can be hard to see the pilot. They are present and ready for battle. This is a really interesting Lego Mech. The overall design looks very sleek. It features a mechanical look with some excellent greebling. The few extra hoses and vent / grill pieces help make this look more believable. Although its feet help it stand, the spindly joints in the hips and knees means that it needs a little bit of support.
For more information you can find the Sandstorm IV over here: https://www.flickr.com/photos/186036005@N06/49932066952/