Scattered throughout Hyrule are stones which create fun whistling tunes when the wind passes through them. Approach them as a wolf and Howl along with their melody. You'll be greeted by a Golden Wolf, who will bid you find him "with sword in hand." Find the location he appears and approach as a human and you will be taught a Hidden Skill.

Howling Stones | Skills

Howling Stones Stone Location: N/A Golden Wolf Location: You'll encounter him automatically on your way to the Forest Temple. Stone Location: From Kakariko Village, begin your ascent of Death Mountain. About halfway up is an open area with many a geyser on the ground and alcoves in the walls. The Stone is rather prominately placed on the path. Golden Wolf Location: Hanging out by Ordon Spring. Stone Location: Lake Hylia, on the cliff with the tall watch tower. Golden Wolf Location: Gerudo Desert, near the entrance to the fort. Stone Location: From Kakariko Village, begin your ascent of Death Mountain. About halfway up is an open area with many a geyser on the ground and alcoves in the walls. The Stone is rather prominately placed on the path. Golden Wolf Location: Hanging out by Ordon Spring. Stone Location: Faron Woods, just outside the entrance to the Sacred Grove. Golden Wolf Location: In the field south of Castle Town. Stone Location: Snowpeak, on the path up the mountain. The Reekfish scent will take you near it, but it shouldn't be too hard to miss otherwise. Golden Wolf Location: Kakariko Village Graveyard. Stone Location: In the Hidden Village, head through the house and into the alleyway with the cucco. Golden Wolf Location: Just outside the entrance to Hyrule Castle. Skills Ending Blow Target a prone enemy and hit A to deliver a finishing blow. Shield Attack Jab the nunchuck or tap the R button to hit the enemy with your shield, stunning them. Back Slice Jump to the side twice, then shake the Remote (or hit B) to deliver a spinning attack from behind. Helm Splitter Shield attack the enemy, then hit A while they're stunned to deliver a jumping slash to the head. Mortal Draw With sword and items away, wait until an enemy gets close and hit A for a samuri-esque instant kill. Jump Strike Target an enemy and hold A to charge up, and release it to strike at a group of enemies. Great Spin With full health, spin attack for greater damage.