Lily Pad

Lily pads are disc-shaped leaves that are featured in several of the The Legend of Zelda games. They are found floating on water and are similar to their real-world counterparts known of the same name.

In some games they feature as a game mechanic (generally as a platform to stand on) while in others they are just aesthetic.

As an Aesthetic Object
The Dark World's Swamp of Evil in A Link to the Past has many giant lily pads. They can be stood on, but they are immobile, they do nothing else, and, as they are mostly found in areas where the water is shallow enough to wade in and Link will normally already be able to swim by the time he gets there, they serve no special purpose. Lily pads in Link's Awakening and Oracle of Seasons are also simply part of the swamp scenery and are not an interactable object. They are found in Goponga Swamp and Spool Swamp, respectively.

In Ocarina of Time, there are lily pads in the Fishing Pond that are also nothing but scenery. The Sinking Lure and the Hylian Loach can potentially be found among them.

Majora's Mask
Majora's Mask introduces functional lily pads. There are large lily pads all over the waters of the Southern Swamp and Woodfall, both in areas with normal water and in areas with poisonous water.

When Link is in his normal form, he can climb and stand on one of these for only a few seconds before it collapses under him. After a while off-screen it reappears.

However, since Deku Link weighs less, as long as Link is wearing the Deku Mask he can stand on one without it collapsing. In fact, due to this attribute, Deku Link can use the lily pads to safely navigate the poisonous waters of Termina's swampland. Doing so is necessary to access certain areas of the Deku Palace.

A similar type of lily pad, under which Bio Deku Babas live, can be found in the Great Bay Temple, or in Secret Grottos. This variety will support all of Link's forms, however it will flip over and toss him off if the Bio Deku Baba is still attached.

The Minish Cap
The lily pads of The Minish Cap can be found in areas where Link must be Minish-sized and there is water, such as streams and puddles in the overworld and the two Minish-sized dungeons: Deepwood Shrine and the Temple of Droplets. Such lily pads can be propelled somewhere, with Link on them, if he uses the Gust Jar to shoot bursts of air in the opposite direction. This is required to navigate these areas. Stretches of water naviagable in this manner frequently have Pestos flying overhead that will attack Link if he draws near.

Skyward Sword
In Skyward Sword lily pads are large enough to support Link, and have pink thorns that branch out underneath.

There are two types of lily pad. One has a small cluster of thorns around the base of a hook-like structure extending from the bottom. The other has a much larger cluster of thorns on the bottom and no hook. Both these types can be found in the Ancient Cistern, and also Faron Woods when it is flooded.

If Link jumps down from a high place onto either variety of lily pad, it will flip over. If a lily pad with the hook-like structure is flipped over with the thorns on top, Link can use the Whip to grab the hook and flip it over again. This does not work on the hookless variety, though.

Link will get injured if he touches the thorns, so as long as the thorns are on top, he cannot stand on it, and the thorns will also block his path underwater. The hookless variety with the large cluster of thorns is often found blocking passages in the Ancient Cistern, and one such lily pad has a Tadtone trapped in its thorns when Faron Woods is flooded.

Trivia

 * The water lily is the real-world counterpart, and the Giant waterlily is even large and strong enough to hold a person, which is likely the inspiration for the lily pad's ability stay afloat with Link on top of it.