Rotten Chunk

The Rotten Chunk is a crafting material that has a 1/3 (33.33%) chance of being dropped from Eaters of Souls, Devourers, Corruptors, and on the Nintendo 3DS version, the Eater of Worlds.

Crafting

Result	Ingredients	Crafting station
Monster Lasagna(Desktop, Console and Mobile versions)	Rotten Chunk8	Cooking Pot or Cauldron
The Beheaded's Head	Soul of Night10 Shadow Candle(Desktop, Console and Mobile versions) Rotten Chunk10	Demon Altar or Crimson Altar
Worm Food	Vile Powder30 Rotten Chunk15	Demon Altar or Crimson Altar
Coffin Minecart(Desktop, Console and Mobile versions)	Any Iron Bar5 Any Wood10 Rotten Chunk10	Iron Anvil or Lead Anvil and Ecto Mist(Desktop, Console and Mobile versions)
Timeless Traveler's Cloak(Desktop, Console and Mobile versions)	Silk20 Rotten Chunk10 Black Dye(Desktop, Console, Old-gen console and Mobile versions)	Loom
Timeless Traveler's Footwear(Desktop, Console and Mobile versions)	Silk20 Rotten Chunk10 Black Dye(Desktop, Console, Old-gen console and Mobile versions)	Loom
Mechanical Worm	Rotten Chunk6 Any Iron Bar5 Soul of Night6	Mythril Anvil or Orichalcum Anvil
Battle Potion	Bottled Water Deathweed Rotten Chunk	Placed Bottle or Alchemy Table(Desktop, Console and Mobile versions) or Alchemy Flask(Desktop, Console and Mobile versions)
Leather	Rotten Chunk5	Work Bench

Though the tooltip says "'Looks tasty!'", Rotten Chunks cannot be eaten. Instead, it can be crafted into Monster Lasagna, which actually can be eaten.
The tooltip could possibly be a reference to how Rotten Chunks are used in Worm Food, which summons the Eater of Worlds.
The Corrupt Statue makes Rotten Chunks available even in Crimson worlds, which allows the crafting of Leather in such worlds.