Scarecrows are a recurring race from the Legend of Zelda series. They sometime appear as living beings, while other times they are inanimate objects.
Two Scarecrows, Bonooru and Pierre, can be found in a fenced-in garden area overlooking Lake Hylia when Link is a child. Here, Link can play a tune for Bonooru on his ocarina, and the Scarecrow promises to remember it. It is implied they are meant to protect the garden by scaring away the crow-like Guay that live around Lake Hylia. Like can also play a much longer song for Pierre which will play at the end of the game after Young Link meets Young Zelda in the Child Timeline (this does not occur in the 3DS remake).
When Link returns to Lake Hylia as an adult, he finds that Bonooru is still implanted in the ground there, but Pierre has managed to wander from Lake Hylia. Link can play the tune he taught to Bonooru as a child again, which, in turn, becomes the "Scarecrow's Song". With this tune, Link can summon Pierre in certain locations, indicated by Navi, to help him reach hard-to-reach places by acting as a Hookshot target. Interestingly in some places Link can summon Pierre even as a child despite the fact Pierre is supposed to still be at Lake Hylia.
Link encounters the Stylin' Scarecrow in the Trading Post and the Astral Observatory. In addition to serving the same function as Bonooru and Pierre in Ocarina of Time, the Stylin' Scarecrow teaches Link the "Song of Double Time" and the "Inverted Song of Time". Link can also dance with him to make time pass to the next dawn or sundown in the three-day cycle, except for on the Night of the Final Day.
Scarecrows appear as inanimate objects in Ordon Village. They act as training dummies, as Link can practice using his various items on them. Ordon Pumpkins are used as their heads and shatter if hit by a Jump Attack or Jump Strike. Link can also destroy the Pumpkin head using items such as his Slingshot, Bombs, Bow, Clawshot, or Ball and Chain. At one point, Link shows Talo, Malo, and Beth how to use a sword by practicing on a Scarecrow. One of these Scarecrow practice dummies can also be found near Croo's shack in Faron Woods. Interestingly, Link can use these Scarecrow at anytime to practice his sword skills, including some of the Hidden Skills he learns from the Hero's Shade such as the Shield Attack, Back Slice, Mortal Draw, Jump Strike, and Great Spin.
Scarecrows appear as inanimate objects in some fields in Hateno Village. However they actually serve an important purpose for the farmers of Hateno Village, to protect their crops from Mountain Crows a species of crow known to steal crops right out of a farmer's hands if given half a chance. The scarecrows apparently serve their purpose as no Mountain Crows appear in Hateno Village thus do a fine job of keeping the village crops safe from thieving crows. These scarecrow are indestructible and cannot be damaged in any manner.
The legendary scarecrows Pierre and Bonooru from Ocarina of Time are also referenced by locations named after them Pierre Plateau and Bonooru's Stand both located together in West Necluda near Kakariko Village.
Scarecrows appear as targets in some stages. Shooting the body will inflate the head, which can then be shot for a significant number of points (maxing out after 8 shots to the body). Attaining maximum points on the first scarecrow of the level will cause a second scarecrow to appear later, and repeating the process will change the final area and increase the number of high value targets.