Lumberjack

In A Link to the Past, the Lumberjacks can be found to the north of Kakariko Village. Two of them are found cutting a large tree saying that they can feel something odd about it. Later on in the game, after facing Aghanim (for the first time), they stop cutting the tree, and if you charge into it with the Pegasus Boots, a hole will appear. When you fall down the hole, you end up in a cave with a Piece of Heart in there.

The Riddle Quest can be started in the Lumberjack's house.

Trivia
The Japanese word for lumberjack (日本語) is prounounced "Kikori", which is an anagram of the word Kokiri. This, combined with the green apparel of the Lumberjacks, leads some to believe that they were in fact the inspiration for the race in Ocarina of Time.