Cursed Chest: the removed cursed chest

The Cursed Chest was a trapped chest from Update 21: it could replace any chest, and touching it would spawn up to three Wraiths scaled to your level. The rewards were 20 to 40 Bones, Fragments, and an extremely small chance to leave with the Ghost fruit. It was removed from the game in Update 22, enemies included.

How to get it

No longer obtainable: the content was removed in Update 22. Back then, a Cursed Chest would replace a normal chest every 4 to 6 minutes, in all seas, at random locations unique to each player. It would spawn even if the original chest hadn't been opened, which meant you had to search the area to find it.

What the chest dropped

By looting it:

The Cursed Chest, a special chest that could replace a normal chest in the game.

20 to 40 Bones
50 to 125 Fragments, in Second Sea and Third Sea only
Beli, the amount depending on the sea and the type of chest it replaced

By defeating the Evil Wraiths and Bone Wraiths it spawned:

4 to 8 Bones (guaranteed)
10 minutes of 2x EXP (rare)
the Ghost fruit (extremely rare)

The Wraiths

Touching the chest would spawn up to 3 enemies scaled to your level, who would immediately try to kill you: Evil Wraiths or Bone Wraiths. Only you, as the chest opener, could damage them, so no one could steal your kill.

Each one gave a lot of EXP, around 7,000 per enemy. It could also happen, very rarely, that no enemies spawned at all: the source suspects a bug.

Where to find them

Sea	Recommended spots
First Sea	Upper Skylands, Marine Fortress, Middle Town, Desert, Pirate Village
Second Sea	Ice Castle, Cursed Ship, the Hot and Cold raid zone, Forgotten Island, Kingdom of Rose
Third Sea	Floating Turtle, Castle on the Sea, Haunted Castle, Sea of Treats

Locations were unique to each player: no one could help you find your chests, everyone saw theirs elsewhere.

Good to know

Known glitch: a normal chest could spawn on top of the Cursed Chest, both landing in the same spot since the Cursed Chest would appear even if the original chest hadn't been looted.

The same glitch, this time on top of a silver chest.

The Cursed Chest glitch appearing on top of a gold chest.

A trick circulated for new accounts: chaining a few Cursed Chests let you go from level 1 to level 50, enough to try the Blox Fruit Gacha. The source discouraged it anyway, since a chest only spawned every 4 to 6 minutes while a basic quest took one minute and gave just as much, if not more.
The Ghost fruit obtained from a Wraith was considered an excellent farming fruit for beginners.
Added in Update 21, removed in Update 22 along with its enemies.