Melon

Melons were introduced in Minecraft 1.8 Pre-Release, the Adventure Update.

Behavior
Melons will have a central stem that slowly grows until it reaches its maximum size, at which point the melon will randomly spawn a fruit next to it if there isn't one already there.

If destroyed, melons will drop 5-7 slices, each will heal one food point.

Crafting
Melon blocks can be crafted out of 9 melon slices.

History
Melons were first revealed in an IGN interview with Notch.

On the Getsatisfaction.com complete ideas for the Ideas section, it has stated that Watermelons will be implemented.