Glistering Melons are an item that is crafted by placing eight gold nuggets and a melon slice in the crafting interface (1 nugget before 13w23a).
They can also be obtained as a reward in the Season 6 Prize Map. A melon drops 3–7 melon slices when broken by hand, using tools, or by the movement of a piston. The name is not a misspelling of "glistening" — glistering is an English word meaning to shine or glisten. They cannot be created by placing a full melon on top of two vertically stacked snow blocks, differing them from their snow golem counterparts. Fortune increases the maximum number of melon slices dropped (the actual amount is capped at 9, so Fortune …
Silk Touch causes the block itself to drop. Melon golems are found in grass and pond tappables with an uncommon rarity and a chance of 1.1% from grass tappables, and 1.8% from pond.
They are used mainly for brewing potions with the instant health effect. It can replace redstone in the brewing recipe for a mundane potion.