If you do go unarmed swordsage with shadow teleporting, or get burrowing or incoproreal or whatever, consider the diabolus race from Dragon magazine. Tail Barb, Multigrab and Greater Multigrab lets you sting one of your PCs with your tail, grapple them but not be considered grappled, and run off with them, dragging them behind you.

Also fun, is get the psionic feat or Dungeonscape variant that lets your monk run by on walls or ceilings. Just don't end your turn there, or you fall off. Plus two levels of drunken master lets you make all kinds of crazy charges. Start on ground level, then charge up the wall, onto the ceiling, then Battle Jump down onto the PCs, then Hustle back the way you came.

Plus, what PC wouldn't like being slapped around by a drunken monk?