Personally I wouldn't be inclined to glue branches together. Honestly, it's going to look like.. Well, branches glued together.
You've got a few options, but the easiest would probably to make it with PVC (plumbers) piping. You can warp it gently with a heat gun (or if you're brazen, very carefully over a gas burner), to give you that branch-like look.
For the hooked part of it, you would make sections from PVC and glue them together (with a suitable PVC glue, and/or by fibreglassing the joins). The knots, you can either make from small pieces of PVC pipe glued on, or build them from something like bondo.
You can even texture the full staff with (either a layer of bondo, or) a soldering iron run carefully over the surface. Or take to it with a stanley knife and sandpaper.
All in all I wouldn't expect that staff to run you over $20-$30, including paints. Make sure you prime your surface before you paint, so it doesn't rub off.
Edit: And sew the binding on to the pants, though make sure you can stick your ol' feetsies through, or things could get awkward.