Not to be confused with the Blood Sky event, a rare gameplay event of the mod.
The Spook is an event that changes a variety of visual aspects in the Betweenlands during the Halloween season.
The Spook is constantly active between October 22 and October 31, and will go away afterward; it cannot be active at any other time of the year unless manually triggered. When active, a variety of natural blocks' textures change to a spookier looking theme. For example, many grasses and Weedwood Trees will turn autumn colored, while Rubber Trees will turn a ghostly white, Sap Trees will ooze with blood, and Roots will turn into creepy tentacles.
The following blocks' textures will change: Blue Eyed Grass, Cattails, Composted Swamp Grass, Cragrock, Decayed Composted Swamp Grass, Double Swamp Tallgrass, Dug Swamp Grass, Fallen Leaves, Hangers, Moss, Mossy Cragrock, Phragmites, Poison Ivy, Roots, Rubber Tree Leaves, Rubber Tree Logs, Sap Tree Leaves, Sap Tree Logs, Shelf Fungus, Sludge, Sludgy Dirt, Soft Rush, Swamp Grass, Swamp Reed, Swamp Tallgrass, Tall Cattails, Weedwood Bark, Weedwood Leaves, and Weedwood Logs.
In addition to the texture changes, the sky will turn a foggy orange color, and a spooky jack 'o lantern face can be seen in the sky. An alternative Halloween-themed ambient track will also play. The moth particles that can be seen in the environment will turn into miniature floating skulls. There are no gameplay changes during this event; it is primarily an homage to the season.
The Spook event can be manually triggered using the following command: /blevent <toggle/on/off> Spook