Two walkers that are featured in the Iron-Grip Marauder game - it's free to play and well worth a look btw. The designs aren't mine this time - I just illustrated these guys! The one on the left is a Terror walker - particularly effective against infantry, and the other one is a Baron walker, effective against - well everything really.
Impressive designs, but the designs make them look like they are easy to board, plus well placed demolition explosives can easily topple them sideways if they saboteur can plant them on the legs.