Den Den Mushi

Den Den Mushi (電伝虫, Den-den Mushi), literally meaning "electric transmission bug", are snails that usually seen with phones or fax machines attached to their shells. They take the place of telephones and other simmilar machines in the world of One Piece. Despite acting like machines, they are actually animals.

They are capable of making a worldwide signal, and many are large enough to make long distance calls.

The Den Den Mushi can come out in many many styles based on where they are and who owns them. For example, marine Den Den Mushi have the marine symbol painted on their face or on their shell. When a person is speaks through a Den Den Mushi, the Den Den Mushi will mouth the person's speech and display the person's emotions. For example, when someone screams, the snail will scream as well. Den Den Mushi are usually active when someone answers the phone, but once they are hung up, they go to sleep. Since being raised by humans gives them access to plenty of food, Den Den Mushi don't mind being used and tamed.

Types of Den Den Mushi
There are many different types of Den Den Mushi.

Baby Den Den Mushi
A Baby Den Den Mushi (子電伝虫, Ko Den-den Mushi) is a fairly small and portable Den Den Mushi. It's good for keeping in contact with fellow comrades in the same area, but incapable of international calls.

Regular Den Den Mushi
The most common type of Den Den Mushi commonly seen. They are too big to carry around but their signal range is much further than that of a baby. They can also serve as fax machines if the right accessory is attached.

Black Den Den Mushi
A Kuro (Black) Den Den Mushi is a type of Den Den Mushi used by the Marines to intercept calls between Pirates or other miscreants.

Golden Den Den Mushi
The Golden Den Den Mushi (ゴールデン電伝虫, Gōruden Den-den Mushi) is a special kind of Den Den Mushi, used to summon the Buster Call attack.

It is a very rare type of Den Den Mushi. After the button on its back is pressed, it sends a message straight to the Silver Den Den Mushi, telling the Marines to start the Buster Call.

So far in the series, it has only been shown to be used twice: once by Spandine on the Island of Ohara, and again, 20 years later, by Spandam. Spandine's use of it was intentional, although Spandam's was not; he used the Golden Den Den Mushi by accident because he thought it was a Baby Den Den Mushi.

Silver Den Den Mushi
The Silver Den Den Mushi is a special type of Den Den Mushi, used as an alarm to alert the Marines through the Golden Den Den Mushi's Buster Call request. It is the largest snail phone, and does not seem able to transmit speech. It is depicted as old and bearded.