I don't think it's true that Mecha always have legs. I'm on mobile and can't look up a better picture, but look for example at the classic tank part of getter

I don't think it's true that Mecha always have legs. I'm on mobile and can't look up a better picture, but look for example at the classic tank part of getter robot https://www.ebay.com/itm/164049621190 https://www.ebay.com/itm/164049621190