Shiisan Puutaa
十三不塔 13 Unrelated Tiles - 1 Yakuman
An opening hand containing total crap. By unrelated, I mean each tile is completely different from each other. Numbered tiles of the same suit are all separated by at less 2 numbers so that no two numbered tiles can make a Chi with the addition of another.
You can only announce this if you are dealer, it is your opening hand, and you just drawn your first tile. The drawn tile must make a pair with one of the 13 unrelated tiles.