Dodongo

Dodongos appear in many Zelda titles. In most games they are generally killed by stuffing bombs into their open mouths

The Legend of Zelda
The second boss of the The Legend of Zelda is the earliest form of a Dodongo, the lizard like creature. The Dodongo in the The Legend of Zelda is vulnerable to what all Dodongos are, bombs. A bomb ingested by the creature will explode inside it's stomach. Two bombs will kill the beast, giving you the second piece to the Triforce of Wisdom.

Ocarina of Time
In Ocarina of Time they are found in Dodongo's Cavern, the Dodongo is a slow enemy which will try to damage you by breathing fire. Swipe its tail with your sword at least two times, and it will explode!

Majora's Mask
In Majoras Mask they are found north of Clock Town. They are larger than their OoT counterparts and subsequently take many more hits to kill.

Oracle of Seasons
The Dodongo makes an appearance in the Game Boy Color game Oracle of Seasons. The Dodongo in this game is vulnerable to what all Dodongos are vulnerable to, bombs. However, just having the beast digest the bombs in this game is not enough. Once the Dodongo eats the bomb, swallows, and has a little indigestion, grab the Power Bracelets and toss the beast into the spiked floor in the middle of the room. Repeat this process four times, and the second Essence of Nature, the Gift of Time is yours.

Four Swords Adventures
The Bosses of the Tower of Flames. Throw bombs into their mouths when they are about to breathe fire. After defeating them, you rescue the Green Maiden.