Leever

Leevers (リーバー, Riibaa) are spiky plant creatures that burrow in and out of the ground and attack Link if he gets too close.

The Legend of Zelda
The Leevers made their first appearance in the original The Legend of Zelda. They reside in deserts and beaches. They will burrow out of the ground upon detecting movement and chase intruders for a while until they burrow back into the earth to rest. Their are two varieties of Leever, red and blue, with the blue Leever being the strongest of the two.

The Adventure of Link
Leevers in The Adventure of Link reside in desert-like terrain as in the first game, but are semi-burrowed in the sand and can be done away with by thrusting down towards them with a weapon, such as a sword.

A Link to the Past
In A Link to the Past, there are two forms of Leever differentiating in color (one is green and one is purple). They operate exactly as they did in the original The Legend of Zelda, but the Purple Leever is very slightly stronger than the green one.

Link's Awakening, Oracle of Ages, and Oracle of Seasons
The same Leever design and sprite is used for Link's Awakening, Oracle of Ages and Oracle of Seasons. They look a little different than their predecessors, (they look more like Spiked Beetles), but their attack pattern is exactly the same as A Link to the Past and the The Legend of Zelda. They also come in two colors, either red or blue, and each with their own attack pattern. The red Leevers will go in a straight line, while the blue ones will zig-zag in different ways to attack Link.

Ocarina of Time and Majora's Mask
The Leever remains much the same in Ocarina of Time and Majora's Mask as it did in its 2D iterations. Just as in the previous games, its only attack is basically shunting you. They are avoidable if you are on Epona or if you move out of their direction, as they only go in a straight line. Their strength is attacking in numbers. If enough are killed a giant one will come out and attack you.

This time around they appear as hideous green blobs with a "mouth" on top.

An interesting point to note is that when Z-targeting normal Leevers on Ocarina of Time, the targeter is green, instead of the normal yellow that targets enemies.

The Minish Cap
Quote from The Minish Cap Leever figurine: "Appears in Castor Wilds, Mount Crenel, etc. These baddies move freely underground and pop out for a surprise attack. Keep your shield up!"

Twilight Princess
Leevers live in both the Gerudo Desert and Hyrule Field, and can be found in the Cave of Ordeals in Twilight Princess. They appear more plantlike in this game and also take a more top-like form. They spin in circles around Link and pop out of the ground if you get to close to them. They only do a small amount of damage and can easily be dodged. They can easily be taken out all at once with a spin attack if you time it right. Their appearance is almost identical to the Leever seen in A Link to the Past, only in 3D.

Strategy
The overall strategy to kill any Leever is for Link to attack it with his sword. One to three hits should send any Leever to its grave.