Ironwood Branch

Increases the Strength of the Hero by 1 when carried.

This unadorned staff appears to be a simple gnarled branch ending at a well-worn knob on oen end and a silver-coated shaft on the other. A single knothole mars the surface approximately halfway up the half. Upon examination, anyone proficient with the staff recognizes that this particular weapon is surprisingly well balanced, and despite its unnatural weight is quite easy to wield.

Source
Tyrande and Furion can find one in The Druid's Arise, chapter 4 of the Warcraft III night elf campaign, Eternity's End.