You were close, "Imperial Walker" is what it's usually called, although there's also a technical name. It's four letters; I think the first letter is 'S'. I can't recall it. Does anybody know that name? I think it's on the Lego box for the Lego version of it. Note the situational irony of my question.
That's called an AT-ST (All Terrain Scout Transport). And I'm not even that much of a Star Wars fan! :P
Urban's right it is the AT-ST
I thought it was either the AT-AT or the AS-ST (I'm not a big fan either)
ATAT's are the larger four-legged ones. It stands for All-Terrain Armored Transport . theres actually a version of it used for aquatic combat as well.
thank you all for your help.
I got it sold so thanks you all VERY much! ^_^