The giant coin[1] is a special kind of coin that first appeared in the Wario games and later in Mario games. Although their appearance varies between the different installments, all of them add one-hundred regular coins to the player's coin counter.
History
Wario Land series
Wario Land: Super Mario Land 3
Wario discovers a giant coin in a secret room in Wario Land: Super Mario Land 3.
Giant coins make their debut appearance in the game Wario Land: Super Mario Land 3. They look similar to regular coins, but are four times bigger and bounce in place. Unlike their smaller counterparts, giant coins are very rare and usually well hidden. They are located in specific levels and can be obtained by hitting a Mega ? Block. Since they add many coins to Wario's coin counter, they can be valuable when Wario makes his wish to Genie at the end of the game.
Wario Land II
A giant coin in Wario Land II.
Giant coins reappear in Wario Land II, although their size was swapped with 10 Gold Coins. They now have a silver tint, are affected by gravity, and flash rapidly. They also produce a characteristic noise once they appear and when they are collected. Giant coins can be found by breaking objects or defeating enemies, just like regular coins. It appears every 64th time either of the previous actions is taken. The giant spear man also leaves a giant coin behind every time he is defeated.
Mario & Luigi series
Giant coins also appear in Mario & Luigi: Partners in Time. Like in Super Mario Land 3: Wario Land, giant coins appear as larger coins, but this time with the number "100" printed on them. They are extremely rare and are only found in ? Blocks in the ground via wide trunks where only the baby brothers can go through. After they are released, they come up to the surface for the Mario Bros. to collect. If they are not collected after a period of time, they disappear. Sometimes, a Tanoomba or Tashrooba disguises itself as a giant coin (though with its face replacing the "100"). When the Mario Bros. get close, the coin turns back into a Tanoomba or Tashrooba.
Giant coins make an appearance in New Super Mario Bros. 2 and are found in the rainbow levels. They appear by flying across the screen as Mario progresses through the area. They look as they do in the Mario & Luigi series. They are worth one hundred coins and therefore reward the player with an extra life. Giant coins can also be found in larger Roulette Coin Blocks.