Forum:Why is Number 17: Leviathan Dragon considered a "staple" card?

I just don't see how it can be considered useful enough to be labled a "staple" card. Just how useful is it? It can't make a direct attack without a card attached to it, and it's only effect is increasing it's ATK by 500. --NickTheForbiddenOne (talk • contribs) 13:51, October 19, 2012 (UTC)